Good at programming competitions does not equal good on the job [video]

http://www.catonmat.net/blog/programming-competitions-work-performance/

by jpn • 9 years ago

372 166 9 years ago

catonmat.net

sghiassy• 9 years ago

Question?

Does being good at programming competitions make you good at interviewing for programming jobs?

Obviously there's some irony in that question. But I also think there's some truth to it as well.

msteffen• 9 years ago

As a former ICPC world finalist who later worked at Google, I would say that practicing for programming contests is almost like cheating as far as Google interviews are concerned. The Google interview format is almost identical to the ICPC practice sessions I did in college.

I've seen this video before, and IMO the extreme similarity between programming contest questions and Google interview questions could explain the negative correlation. Specifically, borderline engineers with programming contest experience are more likely to get hired than borderline engineers without programming contest experience, and therefore the set of Google engineers with programming contest experience includes more borderline people than the set of Google engineers without programming contest experience. Thus the slight negative correlation.

cbhl• 9 years ago

When I was in high school, being good at programming contests meant picking up a bunch of habits that you'd never use at work -- memorizing the same twenty #include lines that include every conceivable STL data struct you'd need; using single letter variable names; no comments whatsoever. If you and the next person come up with the solution at the same time, you might lose simply because the other person could type faster. You have to un-learn these habits for industry.

Just about anyone can get exposure to a set of representative coding questions (see: the USACO training robot, or Cracking the Coding Interview), but training for these contests means spending XX hours a year under a time limit trying to write code from memory (because you don't have time to look things up in the manual).

opportune• 9 years ago

I expect this to be the true root cause of the negative correlation as well. Technical questions are good at rooting out those not good at data structures and algorithms, and good at promoting those that do. However, you can be excellent at solving ICPC questions and not know anything about documentation, object oriented design, OS, databases, anything web related, etc. It's a very specific skill and practicing programming contests optimizes for it.

christophilus• 9 years ago

This is the best explanation of the phenomenon I've read. I think you're exactly right.

xyzzyz• 9 years ago

In my opinion, based on my and my friends' experience, being good at programming competitions clearly makes you very good at interviewing.

I don't think that being good at contests makes you bad at the job, though. Consider the following scenario: assume that skill of being good at contests is completely orthogonal to being good at the job (so the real correlation coefficient is 0, instead of negative, observed by Norvig). Then, since it's easier to to get hired if you're good at contests, the observed correlation coefficient inside a single company will be negative, due to selection bias. Depending on the effect sizes, the selection bias might even make observed correlation coefficient negative even if it's positive in reality (which I think it is).

For a more intuitive explanation, consider a used car market buyer who has preference for black cars (this corresponds to algorithm-based interview process of companies like Google or Facebook). Even though the color of the car should have no correlation with its quality, the black cars owned by that buyer will more likely be worse quality than non-black ones.

thaumasiotes• 9 years ago

Depending on the effect sizes, the selection bias might even make observed correlation coefficient negative even if it's positive in reality (which I think it is).

This is well known in SAT scores. SAT math and verbal scores have a very strong positive correlation in reality; inside almost all colleges they are negatively correlated, because colleges impose threshold effects below and above. (That is, colleges admit students in a narrow band of SAT scores, rather than admitting students who are above a minimum threshold.) You can stylize that into the idea that total SAT score is constant for the students in any given college, which easily explains why component scores would be negatively correlated within colleges.

williamsmj6• 9 years ago

The title of the post understates the claim in the link, which is that, "being good at programming competitions correlates negatively with being good on the job".

williamsmj6• 9 years ago

I tweeted this link this morning (apparently the first time it's been posted to Twitter, so perhaps how it ended up here on HN).

I did so in response to the CTO of Kaggle tweeting "Super confused why we still use resumes. Get 100x the signal from domain profiles (GitHub, StackOverflow, Kaggle, etc.) & real work samples", which ... where to start [https://twitter.com/benhamner/status/883137638084956160].

rquant• 9 years ago

no the statement is ""being good at programming competitions correlates negatively with being good on the job, conditional on passing Google interviews" which is completely different statement.

"being good at programming competitions" hugely positively correlated with "begin good on the programming job" unconditionally

sbierwagen• 9 years ago

Do you have... any kind of evidence to support that claim?

agounaris• 9 years ago

Winning the dunk competition does not make your team be an NBA champion...

BoiledCabbage2• 9 years ago

But winning the 3pt shooting contest is a pretty good proxy for shooting ability.

NTDF93• 9 years ago

And I'm so glad that Golden State Warriors didn't just Hire Kevin Durant for his 3pt shooting abilities. He'd lose to a lot of people who are better 3pt shooters.

rdiddly• 9 years ago

Another sports metaphor: Being a good sprinter doesn't make you a good marathoner.

paulcole• 9 years ago

Also important to remember that good at programming does not necessarily equal good at job.

Excelling as a communicator, being an empathetic person, and having great interpersonal skills are just as (perhaps more) important than how well you can code.

potatolicious2• 9 years ago

It continues to surprise and frustrate me that as an industry we continue to highly prize proxy signals for engineering skill, when engineering skill is so directly measurable.

Why even bother with measuring things that are N-degrees removed from actual engineering, when you can just get people to engineer things?

I know others on HN have been hammering this point home for years, but until something changes it deserves to be repeated ad nauseum: work samples work samples work samples work samples.

Stop with the trivia questions. Stop with the contrived algorithms questions. Ask people to design systems, ask people to defend their designs, ask people to write real runnable code that directly relates to the work they will be doing at your job, ask people to review a real piece of code written at your company, ask people to critique real design produced at your company. Anything but what we're doing right now.

williamsmj6• 9 years ago

It's not that simple.

Many good engineers, especially those who aren't young men, don't have existing work samples they are able to share. Perhaps, by choice or otherwise, they have a personal life that does not allow them to write code for free. And their employers won't allow them to share work code.

And many good engineers are not willing to spend an unpaid weekend writing code auditioning for a job they aren't yet sure they want.

And, as you know if you've ever worked with a disruptive colleague, or had customers, engineering in a team for a product is much more than just writing code.

angersock3• 9 years ago

don't have existing work samples they are able to share.

This, at least, should be fixable.

Don't work at places that won't let you talk about your work and demonstrate your competence.

tptacek6• 9 years ago

That's not what a work sample is.

A work sample is a (usually, hopefully) standardized piece of work you request from all candidates that mirrors the actual work they'd be doing on the job.

There's no reason a work sample needs to be so onerous that it costs you a weekend. What people forget when this comes up for discussion is that interviews are work. In fact, they are themselves onerous work, since they require you to be on-site and intensely engaged in ways you don't have to be to do the actual work of a job.

A work sample, on the other hand, can be done from your home, with a beer next to your laptop if that's how you roll.

The notion of audition work has definitely been abused in our industry. People get work samples that aren't standardized. They get work samples that are later ignored. Work samples don't have objective scoring rubrics. Some annoying companies assign new features for their products as "work samples".

Done carefully, though, with objective and predictable grading and calibrated to offset in-person interviewing time, they're superior to any process we have.

potatolicious2• 9 years ago

I don't mean to propose that people spend their off hours writing work samples - that's unreasonable for all the reasons you've given and more.

What I mean to propose is that we dramatically alter the current on-site interview process used by most companies.

Instead of 5-7 interviews, consisting of 5-7 independent but ultimately equally contrived algorithms questions on a whiteboard, use the several hours you have the candidate to produce real, working code that reflects the work that your company does.

Which is to say, this requires no more time commitment than the existing interview processes at typical tech companies.

If the work your company does is deeply algorithmic, this will be reflected in the work sample produced via this process. If the work your company does is more heavily UX-oriented, this will be reflected in the work sample produced, also.

Instead of "over the course of a full-day on-site round of interviews, candidate produced several short snippets of hand-scrawled code solving various CS textbook problems, which we will now use to infer general engineering ability"...

... you can say "over the course of a full-day on-site round of interviews, candidate designed and produced a module of code that does [X small thing that company does], which can be assessed with the same rigor and methodology we already apply to our existing work and employees"

sidlls4• 9 years ago

While I agree that a focus on "work samples" is inappropriate, I must emphatically agree with the parent's broader point.

The way companies in this industry conduct interviews and measure performance is like an aerospace engineering company testing candidates for satellite engineering on their understanding of the Standard Model (physics) or group theory or some such. There's too narrow a focus on what is required of an engineer in the software industry.

softawre2• 9 years ago

You are allowed to pay somebody for a work sample.

kenning• 9 years ago

I am currently reading "hackers: heroes of the computer revolution" and it seems like this culture of optimizing algorithms ("bumming") comes from the extremely early days of programming, when people were laying the groundwork for all the basic functionality of CS.

kafkaesq5• 9 years ago

Well it's not just that -- algorithms do matter, and a very small number of programmers do move the needle in this industry through their ability to shine in that area.

But the vast majority of the time -- that's not what your company needs at all. You need someone who's smart and reliable, and more to the point, believes in your mission. And who will go in and do all that far from algorithmic, highly unglamorous stuff that keeps your business from going underwater, day in, day out.

But of course - those skills are difficult to evaluate in a short amount of time. So instead companies go for a skill that can be "measured".

A skill like -- you guessed it -- algorithms.

teen4• 9 years ago

I actually like the current interviewing approach... and I feel like we are a silent majority. I think whiteboarding / coding algorithm and design problems is pretty fair and reflective of engineering skill.

tptacek6• 9 years ago

You're the overwhelming majority, which is frustrating, because the method you're advocating for empirically and clearly does not work well.

stupidcar• 9 years ago

How is whiteboard coding reflective of engineer skill? At what time, during any job you've had, have you needed to instantly write code on a whiteboard, in front of peers, in a matter of minutes. Almost by definition, it's not reflective of engineering as actually practiced in a job.

I'm a far bigger fan of at-home coding exercises. Yes, I know, some people get annoyed at these because they think you're asking them to do free work in their spare time. But what other way is there to test people's coding under circumstances that most adequately mirror those of an actual job. E.g. they have a (relatively) unlimited amount of time, they have access to Google, their IDE, etc.

I'd much rather see what someone can come up with, in response to some novel problem, based on a couple of days programming, than what they can hack out on a whiteboard based on thirty seconds of thinking. The former seems closer to what coders are actually required to do, day on day.

thatswrong0• 9 years ago

How do you think that? I think myself a decently productive engineer and I always loathed the fact that I have to study for most of my interviews. Study things that I have almost never used in my actual engineering career. In a situation nothing like actual engineering work.

My favorite interview process (given by the company I currently work at) consisted of one coding prescreen that wasn't terribly difficult, one session where I simply talked with two engineers about past projects I worked on, and then one higher level architecture problem that involved pseudo-code but not some esoteric algorithms.

That interview process, I think, is way more representative of my actual day-to-day work than any algorithm interview I've done. It deemphasizes the ability to figure out / reguritate previously memorized tricky algorithms on the spot (when do you ever need to do that during the work day?) while emphasizing the ability to communicate how and why you make decisions.

Which is an incredibly important part of engineering, way more important than whatever skill whiteboard algorithm interviews test.

gautamdivgi• 9 years ago

The current approach has a huge false negative rate. It keeps out the bad apples but hugely favors marking a lot of good/great apples bad as well. The time invested to study for these interviews is quite onerous in itself. So, I'll say I'm not a fan of the approach.

That being said we do use the method where I currently work to interview. However, the problems are not some made up situation or a test of data structures/algorithms but a set we've encountered in real life.

From what I've heard the whiteboard method isn't really popular with many companies today either but everyone is sticking to it until some other alternative which avoid false positives presents itself.

sidlls4• 9 years ago

It is reflective of skills at internalizing and applying undergrad (and sometimes graduate) level academic trivia in a familiar context. The interview process you and other "silent majority" members think is effective at measuring engineering skill is not, actually.

I really wish you and so many of your colleagues would spend a few weeks with engineers in the physical science engineering disciplines. What we do in this industry is a farce, with respect to engineering.

taejo• 9 years ago

I like it... because I'm good at it, so it's easy for me. However, I get no idea of what working at the company is like (beyond what can be gained from asking directly), and the company gains no information about my suitability for that particular job, since they're assessing me on exactly the same criteria as every other job.

DavidWoof2• 9 years ago

What's ironic to me is that a lot of people are going to see this video and just start using programming contests as a negative proxy signal for engineering skill.

BatFastard2• 9 years ago

Totally agree, and if someone does not have code they can share, they have no passion for programming. Therefore no job with me.

misingnoglic• 9 years ago

And with a work sample, how do you know:

1) how well they work with others?

2) how long it took them to come up with the solution?

3) if they actually came up with the solution themselves

kafkaesq5• 9 years ago

1) how well they work with others?

Whiteboard sessions don't tell you that either. Only whether they got lucky, and you picked a problem they already know (so they can breeze through the solution in front of strangers with confidence). Or if they can at least suck it up, and pretend they enjoy this nonsense for 45 minutes (or 4-6 hours, depending how crazy your company is about this stuff) to get a job.

2) how long it took them to come up with the solution?

Does it matter? Really now. What matters on the job is did you go the last mile, think about the corner cases and pitfalls, and make sure your solution was cleanly coded and documented for the next guy or gal. Not whether you solved that silly HackerRank problem in 35 minutes as opposed to 45.

3) if they actually came up with the solution themselves

This one's pretty simple to sniff out, actually: "So I'd just be curious, why you did X here and not Y?" There's pretty much no way a bullshitter can answer that question.

fatjokes3• 9 years ago

I'm also a former ICPC world finalist and I'm willing to believe this is the case in a BigCo because: 1) Top ICPC competitors tend to be extremely socially awkward, and may not work well in groups. 2) Vast majority of engineering work is very algorithmically simple, thus these folks don't get a chance to "shine".

However, I've noticed that they are popular in prop trading firms, where work tends to be in very small teams or individual. I don't know how their performance correlates to fund performance.

If I were hiring, I'd still prefer to hire at least some top ICPC performers. The hard algorithms are rare---but can make or break your product.

I also think the knowledge learned from programming contests is invaluable. I'd like to be able to discuss bipartite matching or min-cut with my colleagues without eliciting a blank look.

joenot443• 9 years ago

I agree for the most part, but I think it really depends on the product your team is building. I can think of at least a couple companies I've worked at where the hard algorithms weren't rare, they were actually non-existent. The product's success relied on user experience, a solid design, and exhaustively tested and maintained code.

The reality with many companies these days is that the algorithmically hard problems are solved in the frameworks and libraries they use, it's simply not necessary for most engineers to understand their inner workings.

I'm curious, would you prefer an engineer with solid software engineering and design knowledge, or one with minimal experience building real software, but very in-depth algorithm and CS theory knowledge?

fatjokes3• 9 years ago

I agree for the most part, but I think it really depends on the product your team is building.

I completely agree. However, 1) Google---whose CTO is the originator of the claim in discussion---definitely works on hard algorithms and 2) you never know how your product could grow. A feature which could get dismissed as "impossible" might be implementable by the right talent. Presumably these teams don't need to be full of top algorithm folks.

I'm curious, would you prefer an engineer with solid software engineering and design knowledge, or one with minimal experience building real software, but very in-depth algorithm and CS theory knowledge?

Depends on the size of my team and what I'm trying to deliver, I suppose. In general I'd aim for a balance in the team, maybe 3/4 engineering/design + 1/4 algorithms. I feel like it's easier to learn design patterns than how to use algorithms creatively.

raverbashing• 9 years ago

But as much as you need a good algorithm, you need it to be testable, reliable and predictable

This involves some team work

pera• 9 years ago

It depends on what position are you trying to fill: if your business have various hard and general algorithmic problems that you need someone to solve then, hiring an ICPC regional champion would probably be a good thing. But this is not always the case...

I wouldn't hire an Olympic medalist runner to do pizza delivery because: 1) the person will probably get really bored (and may quit or perform bad after some time), and 2) the delivered pizzas will probably be a mess inside the box.

I believe programming competitions would do itself a favor changing its currently ambiguous name to algorithmic competitions. Then engineers, who are also programmers, would be ok with it and we would stop having this kind of threads every few weeks.

That being said, I personally enjoy competitive programming and I do agree that the knowledge you acquire is invaluable :) and I also think that most engineers should practice with online judges now and then to be better at their jobs.

pizza234• 9 years ago

I wouldn't hire an Olympic medalist runner to do pizza delivery because: 1) the person will probably get really bored (and may quit or perform bad after some time)

I think it's a bit more complicated than that. What if Olympic medalists were conditioned to think that delivering pizza is the coolest job that exists? What if their scooters have massaging saddles and 5.1 hifis?

I definitely agree this market (segment) has, in a way, a very misled attitude/approach, but definitely, I think there is an (evil) art in marketing such workplaces.

lordnacho2• 9 years ago

Aren't contests normally under huge time pressure? I would think that a lot of people could solve even quite hard problems given ordinary conditions like having lots of time, colleagues, and reference materials available.

jmcgough• 9 years ago

At the same time, if you've never seen a solution that uses something like DP, you're not going to see a DP problem and think "oh, I can use DP for this". Part of it is ensuring that programmers have awareness of the tools at their disposal, so they can pull them out when they're under a deadline to get something done on time that's performant

hrktb2• 9 years ago

To add on point 2), most big companies have a strong bias against 'smart' solutions. If something is too complex to be fully understood by half the engineers:

a) it won't be trusted

b) it won't be maintainable by any random staff, which puts an additional risk on choosing that solution.

The maintainability argument will usually be enough to can any idea that only few people are comfortable to make evolve.

collyw• 9 years ago

The interview process would indicate the opposite.

_0ffh• 9 years ago

Vast majority of engineering work is very algorithmically simple

anecdotal_evidence+=1 : Am engineer, only algorithmically interesting task I had the last three months was to quickly find all minimal solutions of a given instance of a certain class of constraint graph problems. That's about average, at my job. Four algorithmically interesting things a year. And I guess I might even be one of the luckier engineers.

0xfeba• 9 years ago

I just match APIs up 60% of my time. 20% in 75% useless meetings. And another 20% yak shaving.

kwillets• 9 years ago

While these problems don't come up frequently, I've found that in a typical project anything involving a graph has a good chance of being implemented wrong.

YZF• 9 years ago

I used to spend some time on TopCoder and got to be fairly good but not at the top "red" level... There is some transfer to improved code quality but I think it's generally not something that made a huge difference to what I do as a developer.

There are plenty of people who can do really hard algorithms but may need more time or research. Real life doesn't always present you with the same canned problems that are used in competition and you're not operating under the same constraint. A competition problem typically starts from an algorithm, somewhat like a comp-sci exam question. As a competitor you need to quickly recognize the algorithm and then quickly write an implementation. I'm sure a lot of the best competitive people would draw a blank when presented with a problem that isn't a well known algorithm and certainly wouldn't be able to solve it within the time constraints.

Basically it's a game.

What I'd say is that outstanding performance in programming competition probably correlated to some degree with intelligence. Intelligence correlates to some degree with being a good software developer.

eastWestMath• 9 years ago

Companies don't have 2 hour time limits on solving their hard problems - if you run into hard algorithmic problems in your problem domain, you should just have someone with a graduate degree in CS theory. Let them work out a solution that's actually correct and they can explain why, and then the engineers can implement said algorithm.

richardknop• 9 years ago

This is probably true. I agree. I would aim for balanced teams, some top ICPC performers balanced with people who are better at solid design, creating maintainable codebase and working with business people to define requirements.

curiousDog• 9 years ago

I would disagree that they'd be better at solving hard algorithms as well. The hard algorithms are being solved at the top theory groups at the top 10 schools.

I did a bit of programming contests in school as well and most kids practiced hard and got good at the tricks and patterns of solving those problems. The algorithms were mostly undergrad or grad level at best. They were not breaking new ground.

As to whether top ICPC talent correlates to IQ and capability, Most likely, although the same can be said about a really high GPA though. People like Tomek Czajka will shine in all areas.

I've worked at a couple of the Big-4 companies before and the best programmers I met there were not competitive programmers.

derf_• 9 years ago

I am also an ACM ICPC finalist (our team was 2nd in the world, 1st in North America in my final year of eligibility).

I think there are a few very specific skills you learn in programming contests that are useful in the real world:

1) Once you understand the problem to be solved, you can simply sit down and write the code to solve it. The ability to turn ideas into code in minutes instead of hours or days is invaluable. It lets you try lots of ideas, because the implementation step is easy. You can pick the ones that work and throw the rest away, and you don't mind throwing them away because they weren't a big investment. You don't realize how useful this is until you start meeting people who can't do it.

Our coach always told us that there is at least one easy problem, and someone's job the moment the contest starts is to identify it and bang it out. If we hadn't solved one problem in the first 20 minutes, we were already losing.

2) You learn to write code that is simple and correct the first time. Idioms that avoid special cases. Simple data structures ("No pointers!" was common advice, though of course reality was more subtle than that). Understanding when big-O complexity really matters, and when you can use a sub-optimal solution that's easier to code and reason about.

Sure, someone who is smart can write crazy complex code that only they can understand. But crazy complex code doesn't win contests. If you make a mistake you will burn all of your time trying to figure out what you did wrong, and the worse the code is, the worse of a hole you will dig yourself into. Write simple code that doesn't leave much opportunity for mistakes.

There's a scene in Jack Reacher where Tom Cruise's character says, "James Barr is a sniper. He's not the best. He's not the worst. But he trained non-stop for two years. What does training like that do? What does any training do? Skills become reflex, muscle memory, you do without thinking. It also makes people who aren't necessarily smart seem smart by beating some tactical awareness into them." That's what contest programming does.

3) You learn to identify your limits. There's usually (but not always) at least one problem you should just throw away as "too hard" for the time allotted. You won't solve it, so any time invested in it is a waste. In the real world, where you can't just decide not to do your job, that means you know the difference between when you can go fast and when you need to slow down and reflect. When you need to write a test to really know if the code you just wrote is correct. When it's better to step back and simplify the problem, rather than beat your head against it.

Yes, people like to focus on the "hard algorithms", but really this is not what makes good contest programmers. People aren't deriving Ford-Fulkerson on the fly during a contest. They memorize a set of canned algorithms and apply them when necessary. You learn to recognize and value simple, robust solutions to problems. You carry a toolbox of these wherever you go. This toolbox keeps growing long after you stop competing, and it contains a lot more than fancy algorithms.

Now, there is also plenty you don't learn doing contest programming that you still need to know in a real job. But these are the things I learned that have helped me.

I'm still waiting for the day I need to compute the coefficients of a rook polynomial, though.

FTA• 9 years ago

Look at programming competitions from an assessment perspective: what are they measuring and is what's being measured good or bad for a job?

Ability to work under short time constraints (probably good), to hack out some solution that will work temporarily (good) but probably not solid (bad), to forego much time to consider the implications of design and implementation choices (bad), to develop without communication if solo competition (bad) or without communication outside of the small group of core developers (bad), to build a solution without getting feedback and refinements from stakeholders (bad), and so on.

0x4d464d48• 9 years ago

I haven't done a code competition before but my understanding is that code competitions reward cowboy coding over good engineering practice, i.e. implementing features while paying no heed to maintainability.

When you have that mind set and start dealing with a codebase as monstrous as Google's it sounds like a recipe for some serious technical debt.

pklausler• 9 years ago

As a long-time interviewer, I've learned that a candidate being good at programming competitions means that they're probably good at programming competitions.

It's a weak signal either way for success or failure at interviewing and being able to do the job. Part of the problem, as we've discussed on HN so often recently, is that a programming interview has to waste time with FizzBuzz-style questions just to flag the candidates with great resumes, transcripts, and phone screenings who still actually can't program a computer to solve even a trivial problem.

kafkaesq5• 9 years ago

who still actually can't program a computer to solve even a trivial problem.

Or who get nervous, and freeze up.

pitt19802• 9 years ago

I'm not able to watch the video at my current computer

but its actually really typical that when something becomes an advantage for being selected to a certain pool

the success of the those in the pool after the selection will negatively correlate with that thing

---------

the really obvious example of this is the hockey birthday thing from Malcolm Gladwell's Outliers

people with the earlier birthdays were more likely to make it past each selection stage in becoming an NHL player

but those with the later birthdays who were able to be selected in spite of their later birthdays, were typically more successful after the selection

---------

The authors contend that the strategy might actually work against a team's success because they found that players born later in the year and drafted later actually had more productive hockey careers.

Deaner said the study showed that men drafted in the second half of the year were about twice as likely to have successful careers in the NHL ??? reaching benchmarks like 400 games played or 200 points scored ??? than those born earlier in the year.

"If the team wasn't making this mistake, they probably would have been more successful," he said. "The guys born in the first part of the year are much more likely to be busts."

https://www.nhl.com/news/study-suggests-nhl-has-bias-in-favo...

lordnacho2• 9 years ago

the success of the those in the pool after the selection will negatively correlate with that thing

Could be relevant: https://en.wikipedia.org/wiki/Berkson%27s_paradox

pitt19802• 9 years ago

Yeah, exactly

muh_gradle• 9 years ago

I am familiar with Outliers. I read the book. But I fail to see how this is relevant in any way.

scythe• 9 years ago

It's sort of like Simpson's paradox. It's relevant because the statistical "paradox" (contradiction of intuition) described in Outliers is similar to the one in the video.

kjksf• 9 years ago

He probably meant that people who do programming competitions are more likely to pass Google interview (they'll be better at doing algorithmic questions quickly) but are not necessarily better suited to do the actual job.

Just like hockey players born earlier in the year were more likely to be drafted.

chongli• 9 years ago

I favour the simpler explanation: Campbell's law. [0] If programming contests are favoured, then people will optimize for them. Simplify/generalize even further and you get Goodhart's law. [1]

[0] https://en.wikipedia.org/wiki/Campbell%27s_law

[1] https://en.wikipedia.org/wiki/Goodhart%27s_law

MarkMc• 9 years ago

That's an excellent point! I can think of another example: In the movie "Hidden Figures" the black, female engineers at NASA are much better than their white, male counterparts simply because it was harder for them to get in. Perhaps the opposite is true today of engineering students at colleges with affirmative action?

cma• 9 years ago

Alumni preference is at least as big or bigger a factor in admissions than affirmative action. Many of the schools were segregated not so long ago, so you can guess how that affects the alumni pool.

kenferry• 9 years ago

This suggests that you think there is no perception bias that affirmative action is trying to counteract. You might be interested to know that when people try to correct for bias, they typically undercorrect.

Also, for people coming from more challenging circumstances, getting the same results is literally more impressive.

paulddraper• 9 years ago

It's pretty common for tech conferences to give preference for talks to tech minorities.

Whenever I hear a conference has done this, I subconsciously deprioritize attending a talk given by a minority, since they got in with a lower bar...

Terrible I know, but I'm not sure it is illogical.

js8• 9 years ago

I would tend to agree, and while I was never very good at programming competitions, when I saw some of the winning code on Topcoder, I somehow lost interest. If that's the code I would write if I learned to be better at competing, then I should rather spend time learning something else.

On the other hand, something like Project Euler or even Advent of Code is very nice, if you do it at your own pace, or for learning a new language.

shortleon• 9 years ago

Although, I do think that competitive programmers can become great programmers more often than not.

They practice writing correct for-loops, branches, recursive functions, efficient graph searches, input-output, data structure uses etc. in a very fast pace. To be able to do that requires you to chunk a significant amount of information.

I found that doing stuff very fast correctly makes you learn and internalize concepts quickly and more deeply.

This is all unfortunately anecdotal, I'm not sure how to google for such research (not just in cp but in "learning to do stuff fast improves learning rate").

Yet every instrument I've played and tried to learn, the moment I tried to play stuff fast but correctly (be it drums or piano), I had to improve my technique, had to internalize the rhythm patterns (more complex rhythms are insanely difficult to do fast), memory etc. With it came a significant amount of progress.

Same thing happened to me with language. I was speaking English for 20 years but still had trouble with fluent pronunciation (despite my writing feeling natural), I knew what I had to say but somehow my tongue got all tangled. Yet, when I tried learning some rap songs that use insanely fast diction, my speaking improved up to a point where it felt normal.

kinkrtyavimoodh• 9 years ago

Adding to the good points here, I think coding competitions superstars are also potentially more likely to have a diva-complex, while others are more likely to have an impostor complex when they get into a company like Google. The right amount of impostor complex (where it enables you but does not cripple you) is actually very helpful as it helps you learn and better yourself.

kazinator• 9 years ago

People who enter programming competitions are looking for some sort of glory: to be stars. When they don't get it from the job, they get bored.

I suspect that the people good at programming competitions could easily perform well on the job, if the motivation were there. I don't think it necessarily has anything to do with short-term versus long-term problem-solving focus.

There are plenty of short-term problems that you have to solve on the job to be effective. You're not doing them in competition against anyone such that if you procrastinate, you will lose, so the motivation vaporizes.

Also, since job interviews are like programming competitions, people who are good at programming competitions figure they can easily get a job anywhere, and to do that repeatedly. They are not motivated into working hard by job security concerns.

rkunnamp• 9 years ago

Just like 'There is no such person as Good CEO', but only 'A Good CEO for a particular company, at a particular point of time', there is no such a person as 'Good Programmer', there is only 'A Good Programmer for a particular job, at a particular point of time'.

Context matters a lot. One does not use an AK-47 to kill a mosquito. It is terrible for that job. But that does not make AK-47 a terrible weapon.

Good at programming competitions does not equal good at any programming job, is a more appropriate sentence.

dsfyu404ed• 9 years ago

Have you tried killing mosquitos on the back of a deer[1] standing behind a tree at 400yd. Even the AK with it's heavy cartridge isn't enough. You want a full power rifle, especially if the tree is a hardwood. /s

kpil• 9 years ago

I think that there are personal traits that make people perform good in most situations, but perhaps not all extremes. As continuity is normally good, you try to find those, and change only if you really have to.

A programming competition evaluates almost none of the traits thats doing a marathon run as a highly preforming team.

purpleidea• 9 years ago

Completely agree with Peter. I'm shit at those competitions (maybe not the worst ever) but I think I'm pretty good at my job. But I think there are also some who are good at both.

bit_logic2• 9 years ago

Here's a list of companies that don't do this https://github.com/poteto/hiring-without-whiteboards I hope it's the beginning of an industry wide trend away from these types of interviews.

bluetwo• 9 years ago

Overfitting?

AndrewStephens• 9 years ago

I don't find this surprising. I played around on Top Coder enough to reach the first division but the problems presented were in no way related to my day to day work. While the people that did very well (I never got anywhere once I hit the top grade) might have had an excellent command of very specific data structures and techniques, non of the code would have been very useful in the real world.

If I was interviewing someone, a career as a competitive programmer would not be a detriment but it would not count for very much overall. We are looking for creative thinkers that can work as a team.

CalChris• 9 years ago

The market is pretty good at sorting this out and I'm sure programming competition winners are fairly valued. I've seen more Berkeley, Stanford, MIT, CMU and IIT degrees rise to the top than other schools. I haven't seen any top coders. Maybe they're there and I haven't noticed. But I haven't seen them on resumes that I've culled through.

It's probably something you might list on a first job resume but further on down the road, you'd just list your work and your education.

mcv2• 9 years ago

I once had an online discussion about the difference between competitive programmers and professional programmers, and which were better. Someone argued that competitive programmers were better, because they had to perform in more extreme circumstances. As he put it: they were sent into the forest with a knife to kill a lion.

Everybody else ran with that metaphor. Someone asked what a lion was doing in a forest; don't they live on the savannah? I asked whether he was sure there was a lion; plenty of times I've been sent to kill a lion and ended up having to kill a goat or an elephant instead. Are we even sure it needs killing?

I think that's the difference between a competitive programmer and a professional programmer. The competitive programmer will be much faster with a solution to the given problem, but the professional programmer will solve a better problem.

wlesieutre• 9 years ago

Mountain lions like forests just fine! Unfortunately for them, we chopped most of the forests down.

Assuming you're in the US and somebody tells you there's a lion around, pretty good odds it's not one of the big orange ones.

EDIT: Bay area published yesterday http://www.nbcbayarea.com/news/local/Several-Mountain-Lion-S...

mcv2• 9 years ago

A mountain lion is a very different animal from a lion. Different subfamily and genus, even. I don't live in the US, but when someone tells me "lion", I tend to assume they mean a lion, and not a puma. Though if there's any doubt, that's absolutely something to ask questions about.

dsacco• 9 years ago

That conclusion seems just as arbitrary as the one you're contesting.

lr4444lr2• 9 years ago

In the chapter of his interview in Coders at Work[0], Norvig found that the strongest correlate in the interview process with success at Google was paradoxically to have been given the lowest possible score by one of the interviewers. He surmised that this was because in order for such a person to have even gotten hired at the end of the process, someone trustworthy must have seen so much potential in the prospective hire that he strongly advocated for the person to be offered a position which worked in spite of that other low rating.

Kind of ironic for a company whose product values are so tightly tied to quantitive data.

[0]http://www.apress.com/us/book/9781430219484

andrewla• 9 years ago

A qualitative assessment of that factor is hard because Google doesn't hire the people that it doesn't hire.

Another assessment could be that a divergence of opinion among interviewers is itself a positive sign -- programmers with strong controversial opinions who are willing to hold to them even in an interview setting might be better programmers for that.

A less sanguine assessment is that "success at Google" correlates with people who generate controversy around themselves, simply because that is something that creates visibility.

aoeusnth1• 9 years ago

This isn't surprising - in fact, it would be surprising if it wasn't the case. This fact says nothing about the ability of Google's hiring bar to distinguish between good and bad hires, except that it is not a perfect signal.

lr4444lr2• 9 years ago

Totally agree. It just serves as a useful reminder though not to fall prey to the fallacy of deliberately chasing the correlational measure as a matter of policy.

ubernostrum• 9 years ago

More recently, people who have and are willing to analyze data across many interviewees and interviewers at multiple companies (so they can see ongoing performance of a candidate a company passed on!) have pointed out:

http://blog.interviewing.io/you-cant-fix-diversity-in-tech-w...

After looking at thousands of interviews on the platform, we’ve discovered something alarming: interviewee performance from interview to interview varied quite a bit, even for people with a high average performance ... roughly 25% of interviewees are consistent in their performance, but the rest are all over the place. And over a third of people with a high mean (>=3) technical performance bombed at least one interview.

jpn• 9 years ago

This:

https://news.ycombinator.com/item?id=13739329

bjacokes• 9 years ago

Here are some of the positive qualities I would expect from a competitive programmer compared to the general CS population early in their career:

- knowledgeable at algorithms and data structures

- good at analyzing correctness and edge cases, even on simple non-algorithmic problems (e.g. FizzBuzz)

- accustomed to working hard and learning new concepts. this attribute is not specific to competitive programmer – for example, I'd expect similarly from an open source contributor – but it's higher than for a typical college student.

Some negatives I'd expect, which are fixable over the course of the course of their career:

- over-confidence in code, under-testing

- less skilled in OOP, coding style, version control systems, as well as web development or systems code (unless they have specific previous work in these areas)

- sometimes looking down on gruntwork/rote as beneath them (like the view that pure mathematicians have towards applied math or statistics)

I think that list of positive attributes often outweighs the potential negatives, especially during an internship or in the first year or two of someone's career. After that, I would expect many non-competitive programmers to have picked up on some of those advantages (code correctness, learning new concepts).

I've tried to steer my own interviews away from algorithms (especially DP) and focusing more on giving problems that are relatively straightforward, while still being complicated enough that someone has to write precise code and identify/fix a few edge cases.

WalterBright2• 9 years ago

All job interviews rely on proxies for whether someone will be good on the job or not, because the only way to know is to actually hire them.

All proxies are inaccurate.

blacksmythe• 9 years ago

Also, everyone is convinced that their proxy is the best achievable, although of course they test it only against false positives, not false negatives.

WalterBright2• 9 years ago

everyone is convinced that their proxy is the best achievable

In my experience, people merely hoped their process was good enough. And it usually was. The "we only hire the best" is marketing propaganda and they know it.

softawre2• 9 years ago

Yeah. The best proxy is just to hire somebody as a temp contractor for a month or so if both parties can afford it.

NTDF93• 9 years ago

I have had a bad experience with an algorthmic topcoder.

The guy has a brilliant mind. But he doesn't understand the big picture or why his code would fail when integrated with big codebases.

He thinks his work is "done" when he has written his tiny little code with some queues and trees. Then he leaves it for someone else to integrate and thus really solve the problem.

The best engineers I found were the ones who took ownership of their projects and had the ethic to dig deep. Not the ones who could solve toy algo problems.

bshanks• 9 years ago

I see a lot of comments speculating that there may be something wrong with programming competition winners, but this result might be a statistical curiousity unique to Google. It's possible that for most companies, good at programming competitions could still be positively correlated with job performance. For example, what if most people whom Google hires could have won some programming competitions if they had wanted to (a situation that most other companies are probably not in)? In this case, 'won programming competitions' could be data that is a lousy filter for Google, yet a good filter for other companies.

closed• 9 years ago

Good point, in essence it sounds like one theory people have is that competition winners have over-specialized, but your theory is that there could be floor effects in the range of ability at Google (i.e. the floor is high, many people at Google could win competitions).

samlittlewood• 9 years ago

When I am interviewing:

Candidate having competed in programming competitions - big green flag.

But, if success in competitions is, in their view, their biggest asset - amber flag.

I would extend this to most competitive endeavours.

hajderr• 9 years ago

well if you're not good at programming contests would that entail a contemplating/slow programmer?

I'd rather pick an algorithmist and teach him/her to reflect than a so called "reflectionist" / "slow coder" and teach him/her how to solve algorithmic problems.

I'd be interested in knowing the guy's (catonmat) own reflections and experiences too.

adavidoaiei• 9 years ago

They are two types of business, first type business to business, software made to run internal in a company, the business run on this software, generally in this kind of software you use enterprise frameworks, the second type are business to consumer where anyone can made an account and use application, some software as a service are like that, they are too other types of web applications business to consumer.

When you allow that anyone to make an account and use your application sometimes you couldn't rely on enterprise technology and it's better to write everything from scratch or to customize open source solutions.

What they are testing in algorithms contests: 1.) the algorithm is correct with various test sets 2.) the performance of the algorithm, running time in milliseconds, there you should to know how to measure time complexity of algorithm with O(N) 3.) memory consumed, there you should know how much memory you are allocating for variables, for example a variable of type byte consume 8 bits

I think that programmers which has prizes in algorithms contests are suitable for business to consumer applications because there they will find a challenge, this kind of programmers will be bored to dig in enterprise frameworks.

twii• 9 years ago

Depends also on what job I guess?

x1798DE• 9 years ago

In general, I think there are a lot of things like whiteboard interviews and coding competitions where employers would prefer "good at X means good on the job", but are reasonably happy to settle for "bad at X means bad on the job."

qdev• 9 years ago

My viewpoint is taken from the context as someone who is a reasonably seasoned developer returning to the job market. I never did programming competitions in university, though I surely was someone who fit the profile (computer science guy with a discrete math bent). As part of my recent prep for a job search, I joined one of the programming competition websites and did a couple of contests.

I posit that one of the dangers of spending a lot of time doing programming competitions and becoming very proficient at them is that, perhaps, you can come to believe that "true" programming, some sort of Platonic ideal of programming, is about coming up with the clever insight that solves an algorithmic puzzle.

But, in fact, a fair bit of _commercial_ programming is down and dirty, with databases, and user interfaces, and a lot of the time is really just shuffling data from one place to another, maybe filtering it or combining it with another set of data.

And that's just at the beginning of your career. Later on in your career, success means being able to work at larger scales in a team. That means organizing the code in a way that supports the efficient development of the codebase by individuals like yourself, by your team, by the development group as a whole... And at the architect level, you perhaps are looking at designing the system to support the efficient operation of the entire organization.

So I can easily believe that success at a programming competition does not correlate with long-term success as a software engineer in commercial software development. The two are really very different.

(Btw, I actually found the competitions that I did to be fun, but mentally exhausting. I'd say go ahead and do them, especially if you have an inclination for those types of problems. Just be prepared to use a different mindset for commercial software development.)

aqp• 9 years ago

http://ruberik.blogspot.com/2017/07/no-programming-competiti...

It looks like it wasn't "being good at programming competitions" that was negatively correlated with job performance.

It was "participated in programming competitions".

And there are some more "how to interpret machine learning models" caveats in that blog post.

It seems to me the biggest factor in explaining this is that the people who are just below the hiring line but participate in competitions get a bump over the line. Since there are more people just below the line than above it, the "participates" group is bottom-heavy, producing the correlation.

I do a lot of interviews, and it seems to me that lots of people with experience perform below how they "should", because they're not practiced at solving problems from scratch, they work all day on modifying larger systems. Programming competitions would fix that for them, as would most open-source hobby projects.

Good at programming competitions does not equal good on the job [video]

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