Ask YC: Does interviewing developers leave you depressed?

https://news.ycombinator.com/item?id=747653

by Flemlord • 17 years ago

41 124 17 years ago

news.ycombinator.com

I'm hiring a senior developer right now. Our first interview has a 4-question screen, where I ask them to implement a simple function, implement a recursive function, write a simple SQL select (join across two tables), and create a simple object model (how would you represent a car as an object).

~70% of the "senior developer" applicants fail

We're extremely happy with our process--this is only step 1--and it's been amazing at yielding a great set of candidates for each hire, but two weeks of administering the tech screen to applicants leaves me a bit depressed. (sigh)

noodle2• 17 years ago

do you screen them over the phone? seems to me like it would be much easier and less depressing if you just gave them the work, gave them an hour, and told them to email the results back to you. stuff that is nontrivially difficult such that they can't just search and find answers. they have to know.

edit: i think i'd prefer having to do this myself, as well, because i'm a shy person in person and i find myself floundering when i'm on the phone and have to "explain my thought process" to someone as i'm working through it. i'd much rather write down an explanation.

felipe• 17 years ago

I think "quiz" type of questions are pretty ineffective at filtering out candidates. You do filter out the bad candidates, but great ones could also be left behind. Who knows, the person could be an brilliant developer who got nervous during the interview and had a blank. Or the phone call is breaking up. Or the person is in a non-ideal location. Etc... I would not filter out a potential hire just because the person couldn't remember the SQL syntax on the spot...

For me, a senior developer is someone who is able to work in a TEAM, be dependable (i.e.: The guy who you can call at the 3am with an urgent matter), mentor others and be able to contribute and implement new processes and practices. The technical stuff is important but should not be the main filter IMO.

It also seems to me that you want to apply a certain logic or algorithm to the process. Personally I prefer to call up and just have a conversation with the person (trying to find out the aspects I listed above). Unless I am Google and I am getting a gazillion applications, that's different...

noodle2• 17 years ago

i can agree with this. i don't like quiz types of questions either. if i were to hire someone, i'd rather hire someone who i know i can rely upon to get a job done, regardless of their knowledge. someone who knows how to teach themselves, who is able to learn and learn quickly.

but, i still think that a longer-form, more essay-like quiz is better than grilling someone over the phone and expecting them to continuously talk to you while they're working through something.

tocomment6• 17 years ago

Just out of personal curiosity, you should try to find out if any of these failed candidates are actually skilled developers but there's something about the questions or interview that's messing them up?

For example I consider myself a reasonable programmer, I can certainly do any project put in front of me. But I failed a YouTube phone interview because they asked me to "say" a function for finding the longest common subsequence of a set of strings.

I learned the following issues completely stop me from being able to program:

1. Someone waiting on an immediate answer.

2. Someone watching/listening to my though process.

3. Not being able to experiment with the code on a computer.

That didn't cut it for them because apparently at YouTube a lot of your programming is done over the phone (sarcasm).

I guess my point is, try to think of the exact tasks this hire would be doing, and ask them to do that. Will they really be writing recursive functions often? Also if possible give them a take home project, so they can work in a more natural environment.

allenbrunson• 17 years ago

oh man, this is my downfall as well. hearing stories about the way google conducts interviews convinces me that i'll never get in there, or anywhere like it.

i'm perfectly willing to write code as part of a job interview. just not on a whiteboard or over the phone.

_pius2• 17 years ago

i'm perfectly willing to write code as part of a job interview. just not on a whiteboard or over the phone.

why not on a whiteboard?

soc• 17 years ago

I agree. When I first meet someone over the phone or in person I'm in a social mood and prefer to talk rather than do a code dance for them.

Once I'm alone at my desk though it's easy to get down to business.

Think it would be cool if companies just said show up to work, and you work for free for the first week. After that both parties can decide if they want to continue.

zeckalpha• 17 years ago

That's basically how open source works.

HeyLaughingBoy3• 17 years ago

Maybe it's just me, but I tend to immediately discount any advice or proposals that suggest I work for free.

tocomment6• 17 years ago

That's a really good idea. If wish we had that too.

stanleydrew• 17 years ago

I know a bunch of smaller startups that do the "come in for a week and we'll decide" out here in the bay area. Peanut Labs, e.g.

Pistos2• 17 years ago

I thought it was very common practice to have a [paid] probation period, where the company is free to keep someone or let them go. Usually the period is less than 6 months. That seems a sensible approach to making sure your hiring decision was good or not.

plinkplonk6• 17 years ago

"you should try to find out if any of these failed candidates are actually skilled developers but there's something about the questions or interview that's messing them up?

hard to think of a halfway competent developer failing to answer

"where I ask them to implement a simple function, implement a recursive function, write a simple SQL select (join across two tables), and create a simple object model (how would you represent a car as an object)."

in about a minute or so all told, even verbally, over the phone.

"YouTube phone interview because they asked me to "say" a function for finding the longest common subsequence of a set of strings."

This is (ever so slightly) different from OP's ultra simple questions above , but otoh , YouTube has a lot of tough algorithmic problems to solve. I am not sure what position you interviewed for, but the question itself sounds decent for a position that could involve algorithms and searching and so on. Now if the interview were for a job involving "code up a basic enterprise app" I can see how it could be inappropriate.

All that said, I am not a fan of extended phone interviews , but asking very basic questions (as the OP seems to have done) eliminates a surprisingly large number of looks-good-on-paper-but-can't-code-for-nuts type "programmers".

The key to not getting depressed is not to waste any time on people who can't answer ultra basic questions. If in 30 seconds you feel someone is too incompetent, shut the conversation down politely. Spending long periods of time with incompetents is depressing.

One solution is to send a (moderately complex) programming problem by email and ask them to send code back. This will weed out a lot of people without wasting your time.

pj7• 17 years ago

I agree. The questions the OP asked are all very easy. It'd be easy to describe a function to find the longest common subsequence of a set of strings as well. The reason such a question is asked is because it isn't something that we do everyday and how we solve problems that we don't immediately know how to solve is what sets good programmers apart from bad programmers.

I find anyone who immediately blames the environment for their lack of ability to answer the questions correctly to be suspect. These types of complainers are externally motivated and will never accept fault for their lack of capabilities. "You should have asked me in a different way." or "I need to be taught differently" or "There's too much pressure"... look, you can come up with whatever excuses you want, but the fact is, you can't solve the problem and what we are looking for is someone who can solve problems.

Case closed.

nibrahim• 17 years ago

>One solution is to send a (moderately complex) programming >problem by email and ask them to send code back. This will >weed out a lot of people without wasting your time.

This is I think the best solution. A friend works at a company here called Tachyon and they have this part as part of the form on their jobs site where you can apply for jobs. http://tachyon.in/jobs.html

blankity_blank• 17 years ago

because they asked me to "say" a function for finding the longest common subsequence of a set of strings.

That's rough, asking for a solution to an NP-hard problem over the phone? http://en.wikipedia.org/wiki/Longest_common_subsequence_prob...

Or maybe they were just expecting you to say "for each combination of subsequences of each string, check if they are equal ..."

mquander2• 17 years ago

We may be mishearing their intended formulation, which could have been asking for the longest common substring (described here: difference is that subsequences don't have to be entirely contiguous, just in the same order.)

http://en.wikipedia.org/wiki/Longest_common_substring_proble...

That's an interesting problem with some simple solutions worth understanding. I don't think it would be unrealistic to expect a high-quality programmer to be previously familiar with it, or, if not previously familiar, to be able to make progress toward the DP solution with some thought.

tocomment6• 17 years ago

No, they wanted a working function. I used Python :-(

jasonkester2• 17 years ago

No, that sounds about right. 70% of the people you interview will not be able to code their way out of a sack. It actually sounds like he must have done some form of initial screen just to get the success rate up to 30%.

philwelch9• 17 years ago

I got asked to write a fibonacci function in an interview once, but they were kind enough to say "go sit at your text editor and write it and then read it to us". I was still flustered a little (since I wasn't sure whether to just talk through it or actually say "int fibs open-parent int n close-paren open-brace...") but apparently I passed the phone screen. I did remark that the naive recursive approach was a terrible algorithm, which may have helped.

Of course, I failed their day-long battery of on-site interviews later. But I did get interviewed by the entire development team, plus the CEO. That was kind of fun.

adam_feldman• 17 years ago

Companies could always do the interview on a tool such as etherpad.com so they could watch the interviewee write.

agotterer• 17 years ago

We are currently going through the same daunting process trying to hire a PHP developer at CollegeHumor. I would say 70% of the applicants we interview cant answer basic computer science questions. We don't give a written technical test. We don't expect a developer to be able to code on paper. In a real environment they have access to tools, compilers, docs, etc. It's an unfair and unnecessarily stressful test.

Good luck with your search.

Shameless plug: If your interested in a development position at CollegeHumor in New York City... Email techjobs@connectedventures.com.

edw519• 17 years ago

Outsource Step 1 with an on line programming screen. There are many companies that do this. Sure you'll have to pay for each one, but they will weed out the bottom 90% pretty quickly.

akaGOMEZ• 17 years ago

I've been working for 3 years as a front-end developer and somehow have managed to pick up all of those skills minus the join (just started learning SQL last week). Maybe your pool of samples is tainted. Where do most of your applicants come from?

martincmartin• 17 years ago

I have kids, and whenever I do interviewing, I get worried about their future. I think the secret is to get them to feel passionate about something; as long as they have the motivation, they'll want to learn. But how to do that? And what if I fail? I shudder to think they'd have to stay in some of the crappy jobs I've been able to leave.

kmano82• 17 years ago

For my current job (for an entry level position), I took a one hour test asking to do pretty basic coding prior to interviewing with anyone. It asked to find errors/poor practices in a code snippet, some quick logic/binary operations, and a larger question involving linked lists that required a few minutes of planning before I began writing code out.

This was a comfortable setting for me. Though in previous interviews, I would completely freeze when someone wanted a technical explanation, simply because I need a moment to collect my thoughts, and it's difficult to do so when someone in front of you is looking for an immediate answer.

larryfreeman• 17 years ago

Senior Developer does not always mean coder. It means, in my view, senior-level experience and senior-level judgment.

What are the job requirements?

I was a manager for 10 years and didn't code except to fix bugs. When I coded, I used C/C++. As a senior manager, I oversaw the JavaEE application strategy at Sun.

At any rate, today, I am a Senior Developer at a start up that uses LAMP. I would have no problem answering your questions today but it took me a full month to get back up to speed.

It may be that you are focusing on the wrong questions, it may be that your job description is attracting the wrong candidates, or it may be that you are not promoting the job in the right channels.

Good luck.

_pius2• 17 years ago

Yes, it is depressing.

That said, I've had success with doing the pre-screen in a Campfire room and asking them to Pastie/Gist their code into the room. That way, you eliminate some of the weirdness associated with coding over the phone, but you maintain much of the immediacy.

Flemlord3• 17 years ago

That's exactly what I do. The first interview is over the phone and they type out their answers over a WebEx link.

Leon2• 17 years ago

Steve Yegge's post on this is apt and may help those who haven't read it.

http://steve-yegge.blogspot.com/2008/06/done-and-gets-things...

mebigfatguy• 17 years ago

My experience has been identical to yours. Ask simple questions, get constant failures. In bad times, the signal to noise ratio is completely out of wack. A recession is the worst time to hire people.

donaldc• 17 years ago

I'm not sure why that's depressing. You've managed to filter out the majority of people you'd not want to hire with just a simple set of tests.

Perhaps a way to screen out many of these people without spending the time administering the screen is to have a simple coding test that these people complete before you'll even have them in for an interview. A couple places I've interviewed with did this, and they both expressed high satisfaction with the reduction in interviews of hopeless candidates that resulted.

vax_1112• 17 years ago

Part of it may be your questions, and part may be HOW you're asking (e.g. over the phone, or putting someone on the spot).

2) Not a lot of people write SQL by hand anymore. I used MySQL for years, long ago, and never wrote a join. Then ORMs came along and handle joins automatically, so I've still never written one. So not being able to do it without looking it up doesn't really tell you anything. I've written far, far more complex things than an SQL join statement. A more pertinent issue I'd be checking for is whether user input is properly escaped to prevent SQL injection -- again, not an issue with ORMs, but an issue when building SQL query strings by hand.

1) A lot of people use languages where recursion is unusual (i.e. NOT Lisp). Even a senior developer (especially of something like PHP) might not recall this, not having actually written a recursive function for years.

3) Representing a car as an object: A lot of software people don't know hardware, so the confounding part might be recalling various attributes of cars and how they relate to each other.

Also keep in mind that many introverted people get very uncomfortable when someone is waiting on them. This can make it difficult to concentrate at all. Being asked to perform on demand is normal for a musician but foreign to most programmers. On top of that, it's usually in an unfamiliar environment, such as verbally or on a whiteboard -- imagine asking a violinist to play on some lines you drew on a piece of paper.

PG, RTM, and TLB would probably fail your test -- they don't use SQL, they use flat files.

jockc• 17 years ago

Sorry, we decided to go with another applicant. We'll keep your resume on file.

vax_1112• 17 years ago

As noted, there are numerous expert programmers who couldn't do an SQL join in a live interview.

Besides PG, RTM, and TLB, most or all of the Linux kernel programmers, including Linus; Pete Norvig; embedded systems programmers; and on and on.

You could find a lot of people who can handle the SQL you need while screening out brilliant people who are FAR more capable, but just happen not to know item X.

plinkplonk6• 17 years ago

"I used MySQL for years, long ago, and never wrote a join."

Scary! I wonder about your definition of "used", if you used an RDBMS in a non trivial app "for years" and never wrote a join! The database design must be very ... unusual :-).

And this was in the days before ORMs :-D.

" Then ORMs came along and handle joins automatically, so I've still never written one. "

I've never yet seen a non trivial RDBMS based app where the existence of an ORM absolved developers from having a good grasp of SQL when they needed to drop below the abstraction layer provided by the ORM.

"So not being able to do it without looking it up doesn't really tell you anything."

It does, really! ;-).

"PG, RTM, and TLB would probably fail your test -- they don't use SQL, they use flat files."

The interesting thing about this statement is that it shows one way out of potentially being asked to code on a whiteboard/over the phone. If you have a PhD' from MIT and/or have a strong track record of writing Open Source software, creating and selling a startup, build robots (and electric unicylces ) for fun etc, in other words, if you can show , well before the interview, that you are as good or better than the job demands, you are very unlikely to face the "find the longest subsequence in a string" or "write a join" type questions. But then if you could do all that why would you look for a job?

In my case, after writing some open source software, (and posting an url as the first thing in my cv) I've found that these kind of elementary questiong simply drop away. When a few thousand people use your code everyday, people know you are good.

The OP's post is about when all you have is a cv that looks like the last 100 cvs you reviewed, and people who can't answer simple questions about how to write a join (hence his depression).

enjo2• 17 years ago

I would fail if this was a 'live' screening. It's rare that I write SQL by hand, and remembering the syntax for a JOIN is something I pretty much always look up. I just don't do it by hand very anymore.

I'm a very good developer (my track record would suggest as such), but I would fail at least one part of this test due to the simple inability to remember elementary SQL syntax.

The interesting thing about this statement is that it shows one way out of potentially being asked to code on a whiteboard/over the phone. If you have a PhD' from MIT and/or have a strong track record of writing Open Source software, creating and selling a startup, build robots (and electric unicylces ) for fun etc, in other words, if you can show , well before the interview, that you are as good or better than the job demands, you are very unlikely to face the "find the longest subsequence in a string" or "write a join" type questions. But then if you could do all that why would you look for a job?

That's just not true, particularly at the larger companies out there. Amazon, for instance, has a rigorous process that you can't (more or less) circumvent. It involves a lot of saying algorithms over the phone. It was one of the most challenging interviews I've done in my life. Not because of the content, but because of the method.

jasonkester2• 17 years ago

"I used MySQL for years, long ago, and never wrote a join."

Wow.

Note to self: start asking candidates to write SQL in interviews.

It had just never occurred to me that people who spend their entire lives talking to databases wouldn't know how to talk to them directly.

And really, you can get pretty much any piece of information out of a database using just four keywords. It's the least memorization of any language in history. SELECT, FROM, WHERE, and for extra credit, LIKE. That's it. That'll get you any non-aggregate dataset you could want, joined or otherwise.

Learn IN and GROUP BY and you've got everything else you'll ever need for reporting. It's just the simplest language ever.

vax_1112• 17 years ago

> if you used an RDBMS in a non trivial app

Depends on what you mean by "trivial".

You can use a database for most of the things most websites use them for without ever using a JOIN. It just takes application logic instead of SQL.

Sites like this aren't exactly heavy on the SQL. This site doesn't even use SQL. Something like Reddit or Slashdot would, but still wouldn't need JOINs.

> I've never yet seen a non trivial RDBMS based app where the existence of an ORM absolved developers from having a good grasp of SQL when they needed to drop below the abstraction layer provided by the ORM.

You don't have to drop below it; you can go "above" it into the application layer.

> If you have a PhD' from MIT and/or have a strong track record of writing Open Source software, creating and selling a startup, build robots (and electric unicylces ) for fun etc, [...] But then if you could do all that why would you look for a job?

Let's consider the case of someone with a PhD who ISN'T famous, and then you give him some kind of SQL test and he fails. "Man, what a load of bullcrap his PhD is! He can't even do a simple JOIN!"

There are a lot of people who aren't "PhD millionaires" or famous open-source magnates and yet are vastly capable. A lot of them don't write joins. And a lot of people who CAN write joins can't do a bunch of other stuff.

You know what else PG doesn't do? CSS. He runs a website but doesn't use CSS or SQL.

So, once again, the danger of using any litmus test is you can end up filtering out extremely capable people who don't do X (but could obviously pick it up quickly), while passing minimally-capable people who CAN do X.

mquander2• 17 years ago

Well, if you're using ORMs to handle all your SQL needs (and they literally must be handling all your needs if you're never writing anything with a join) then I don't think that you actually have a working knowledge of SQL in any sense. There are certainly plenty of jobs which require that knowledge, and I'm not sure an employer would want someone who didn't have direct SQL language experience.

To be honest, I don't understand how you manage not writing joins even if your ORM is perfect and flawless. I use the SQL prompt like an interactive debugger, writing queries to look at the internal state of my database.

(I assume that the original post refers to applicants that listed "SQL" somewhere on their resume, or else he wouldn't be asking SQL syntax questions -- I hold that if you have "SQL" on your resume, you had better know how to write a join.)

vax_1112• 17 years ago

> then I don't think that you actually have a working knowledge of SQL in any sense.

Of course I have working knowledge of SQL, that's how I used MySQL back when we had to write things by hand. I just don't have a working knowledge of JOINs. I could look up the syntax if I needed to use it. [Looks it up] Looks easy enough.

There are numerous SQL commands most users of SQL would probably need to look up.

Arbitrarily deciding that having not-used X means you don't have a working knowledge is a fallacy. Someone else could arbitrarily decide the litmus test is stored procedures. MySQL didn't have those, so instead of using them we had to code at the application layer, and just happened to use application logic in places of JOINs as well.

I don't even remember if MySQL had joins, or non-buggy joins, a dozen years ago. Other people would say, "it doesn't have transactions, so it's not a real database", et cetera, et cetera. You work around limitations and get used to doing things a certain way.

warfangle• 17 years ago

I don't think the violinist comparison is fair.

Any violinist worth their salt has practiced sight reading to death. Absolute death. It's difficult to do, yes, but if you're playing in any sort of group situation (orchestra, etc), sight reading is extremely important.

Unless you're saying "I drew some lines on this piece of paper that represent the strings on the violin; I want you to play the piece of paper like you would the instrument." In which case it's a worthless interview. Whiteboards are fairly common for code snippits and pseudocode at most of the jobs I've worked. Pieces of paper with representational lines for the strings are used as individual studies (e.g., sheet music) - not for collaboration. That's usually done in jam-format..

vax_1112• 17 years ago

> Unless you're saying "I drew some lines on this piece of paper that represent the strings on the violin; I want you to play the piece of paper like you would the instrument."

Yes, that's it.

> In which case it's a worthless interview.

I'd say the same applies to whiteboards. I have never sketched out code on a whiteboard except in an interview. Of course you can do so and become accustomed to it, just like you can finger a paper violin or piano.

planck2• 17 years ago

"PG, RTM, and TLB would probably fail your test -- they don't use SQL, they use flat files."

Well, then they likely wouldn't be a good fit for the position the OP is hiring for, since it requires using SQL, not flat files.

vax_1112• 17 years ago

It would be nice to see who's upvoting this so I could add them to an IDIOTS file.

Any of the above people could obviously EASILY pick up whatever SQL you happened to be using. RTM could wipe the floor with you, the OP, and everyone else on your team.

If your interview process filters out people like RTM, your filtering is broken.

philwelch9• 17 years ago

"A lot of people use languages where recursion is unusual (i.e. NOT Lisp). Even a senior developer (especially of something like PHP) might not recall this, not having actually written a recursive function for years."

There are tons of languages that support recursion. Whether or not you use it is a function of the problem, not the language. (I'm not counting tail recursion since I consider tail recursion to be a functional way of expressing iteration.)

"Representing a car as an object: A lot of software people don't know hardware, so the confounding part might be recalling various attributes of cars and how they relate to each other."

Well, if I was given this question in an interview, I would ask, "are we building a CAD program or a car-racing game"? CAD programs (I've never written one) would probably have a CADObject class for all drafted objects that the car parts and the car itself would inherit from, and you'd have to discuss not only what was in the car but where it was connected, so just saying that it's a composition of "engine, body, brakes, air filter, etc." would be insufficient. A car-racing game would just have a car object with a shape, performance characteristics, and be able to hold states for its physical motion at a given time, as well as being able to take messages/method calls for things like "pressing the turbo button" or "emergency brake" or "shoot a missile" (depending on the racing game). You can build an entirely sensible object model for a car and be totally wrong if you don't know what you're building it for.

vax_1112• 17 years ago

> There are tons of languages that support recursion

Obviously. But I don't remember ever writing a recursive function in PHP for a website.

lutorm3• 17 years ago

Are you depressed because your filter has proven very effective? It seems you should be happy. ;-)

The thing to worry about with a very discriminating filter is, like tocomments post, whether you are filtering for something different from what you really want...

gstar2• 17 years ago

Not depressing at all, completely representative of the job pool.

The technique you're using isn't common - a lot of traditional companies don't interview on skill and technique (like Google do).

Backing up your 70% of failures, we recently hired a fashion designer at our startup (we're in an interesting market!) I decided we should use the same kind of interview we would for a developer.

Everyone we interviewed was completely baffled, but it really sorted out the wheat from the chaff. At least 80% of the people we interviewed couldn't do what they said.

Thankfully though, we've ended up with someone who is really incredible. In fact, I think she has the 10x higher productivity that us developer types talk about, and her old employer is trying to hire her back.

tl;dr - looks like you've got a normal pool of applicants!

clistctrl• 17 years ago

what is an objective interview for a fashion designer like?

gstar2• 17 years ago

Difficult. IANAFD so this may be slightly technically inaccurate:

We got them to actually draw something (called a flat) from a half-drawn garment, draw a full flat from scratch, identify trends from a series of photos, pick textile colours from photos, identify designers from "signature" garments, have them debug a spec. to see if a garment was reasonable (say the spec called for a notion like a chunky zip on an unsuitable fabric), and a few other things.

known• 17 years ago

How will the interviewee know that interviewer is smarter than him?

californiaguy• 17 years ago

If you're going to put someone in the coding hot seat like that, at least give them the decency of having 30 minutes alone with a computer.

steveklabnik• 17 years ago

Speaking of someone who's basically right out of school, I can tell you that I probably wouldn't hire most of my classmates. It _was_ depressing.

kmano82• 17 years ago

In reference to the post I made directly above yours, a classmate of mine got an interview with my employer about 3 months after I started. The HR guy approached me after his interview, and told me he left the entire linked list question blank.. no pseudo code.. nothing. I was embarrassed.

vaksel• 17 years ago

I think the best solution is to ask the questions in as many possible ways you can think of.

Some people are great at coding, but suck at whiteboard, others aren't comfortable talking about their thought process.

So why not give them numerous ways to show their stuff? Have them find bugs, have them code on whiteboard, have them write code in a compiler, etc etc.

Your goal is to find a good programmer, not a programmer who is good at white board.

andrewf• 17 years ago

Yes. I used to do the chatty bit first before subjecting interviewees to the "technical evaluation"; it seemed polite to engage people first.

That was depressing. At least I found out the technical evaluation was worth giving. An astonishing proportion of people that came off well in less technical conversation would utterly flunk the test.

I'm not talking minor errors caused by interview pressure. I mean people with "5 years of C++ experience" writing void reverse_string(char* in) { char b[] = new char; b = in; ... }

Eliezer• 17 years ago

Good developers get hired and removed from the pool. Bad developers go to the next interview.

http://lesswrong.com/lw/gy/you_are_not_hiring_the_top_1/

Leon2• 17 years ago

That doesn't imply the top 1% isn't there; just that they are more likely to be under-represented. Also, programmers are prone to move to new areas that are more interesting, especially the top/best, so that can skew it back in favor of the upper echelons. It always seems that the mid range to bottom developers are more likely to find somewhere and stay, as they have so much trouble finding a new place to go to. They are the ones that have 'stickyness'.

What is the biggest factor, from what I can tell, is that the best don't send out their resumes but get poached by other companies or use their networking to land a job.

kwamenum86• 17 years ago

This theory may also apply to VC funding.

DanielBMarkham• 17 years ago

I would be careful with your questions. There's a lot of bias that you can create without being aware of it.

I once had an interviewer ask me for the five rules of database normalization. Beat the heck out of me at the time -- I was just drawing a blank. I could do the work all day long, but I couldn't remember the stupid names he was looking for.

Similarly, I had a guy ask me to name the seven categories of this course he was interested in that I had taught years ago. Same deal -- just couldn't recall it, although I was very familiar with the material and had no problem teaching it.

The problem with memory questions is that they bias against people who don't currently have the answer in working memory. Simply because somebody has done something recently is no indicator of performance. The best interviews warm up on general questions about the material before diving deep. That gives a candidate time to "change gears"

I also very interested in "why" questions over "how" questions. Classrooms and cram-lessons are really good at "how" questions -- it takes some degree of actual work to understand the "whys" of something.

I've interviewed a lot of developers over the years. 99% of them really aren't anywhere near as good as they think they are. That's sad, but it's also an opportunity for developers who care about their work to get ahead. It doesn't take much ongoing effort to be truly outstanding.

anigbrowl3• 17 years ago

Flemlord, a lot of responses seem based on hypotheses about what a good answer would have been. Could you follow up and give examples of what you'd have considered correct?

My hobby-programming experience suggests...

simple - int add(int a, int b){int result; result = a + b; return result}

recursive - um, I like fibonacci sequences: void fib(int term){if term = 1 return 0; if term = 2 return 1, else return fib(term - 1) + fib (term - 2)}

SQL join: no idea, I haven't used SQL for years. I assume you mean something like for(i = 0; i < table1.length; i++) do {newTable.fullname[i] = oldtable.firstname[i] + anothertable.lastname[i]}

Car as an object: well I guess I'd have a struct with variables for size, weight, power, turning circle and so on, and methods for accelerating, setting direction [steering heading, speed (forward and reverse, or multipliers for forward gearing)] and braking...then I'd have create multiple instances of that object using a table of values...do you make racing games?

I'm not looking for a job, but I'm interested in knowing what sort of answers you were after. The above seems super-simplistic to me, I'd feel nervous they were trick questions of some sort and the obvious answers are actually the failing ones.

tocomment6• 17 years ago

Join question:

select * from books join authors on books.author_id=authors.id

Now you get the fields from each table in your result matched up correctly.

philwelch9• 17 years ago

Your fibonacci algorithm is crap. You're tree-recursively calculating the exact same values over and over and over and over again. Just try running it sometime on a large n if you want to test your computer's ability to stall and ramp up the cooling fans.

"do you make racing games?"

That's a question to ask first, not second. Maybe he's making a "Pimp My Ride" style game where the actual driving part is less important but you need detailed modeling of the seats and the ability to add a bunch of random shit to the interior of the car. Maybe he's making a CAD tool for people to do body design, so you need to be able to do computational fluid dynamics on it and test weight balances, but also be able to visualize it in high resolution to see if it looks cool and to print mockups for focus groups to say "this looks like a kickass car".

anigbrowl3• 17 years ago

Agreed, but this is the very question I'm getting at - does Flemlord want to know the quality of algorithms someone naturally comes up with, or is this just to screen out the total BS artists?

Hence my mention above of how it feels like a trick question. I really don't know whether the interviewer wants the autistic-but-informative answer or the quick of-course-I-know answer. Trying to guess what sort of answer you are seeking induces mild panic in me: I don't know you, but if your response in an interview was 'what a crap algorithm' I'd be thinking 'this guy is a bit Machiavellian...'.

I mean, I can think of a much faster way (than this) to get a given term in the fibonacci series using a loop, but this one recurses, which was what was requested - I had to quickly choose a problem domain in which to demonstrate it. Towers of Hanoi would have been more impressive, but I don't know if I could just rattle that off correctly, verbally. See what I mean?

zackola• 17 years ago

70% sadly sounds about right. end depression by making the screening process as quick as possible.

rjurney• 17 years ago

Interviewing leaves me depressed. I just spent most of an hour proving I can't verify whether a tree is binary. Mostly, we didn't focus on anything relating directly to the position or talk about my experience in any way. We proved that there are holes in my education pertaining to basic CS, that I never encounter on a daily basis as a web developer. I guess the rest of the stuff was taken for granted.

I understand that these tests can be important, but I can't help but feel that I will fail to qualify for any position that requires me to hold a host of basic CS algorithms in my head, but that I could still do a good job in the position - because I'm very good at learn as you go, and have learned lots of higher level stuff while building elegant, complex systems - without knowing how to verify a tree's binary nature.

jerf• 17 years ago

The only ones that somewhat depress me is a particular class of bad developer: Fresh out of college, these people have their curriculum nailed... and know absolutely nothing else.

One example that really struck me was an interviewee that I asked to write a simple pre-order traversal on a seven-node tree that we print out for our interviews. Instead I got a moderately lengthy and correct description of how to search for a value in a sorted binary tree. Correct, except for A: it wasn't the question I asked and B: immediate visual examination of the tree we were looking would reveal it was clearly not sorted. Other things in this interview led me to the conclusion that I got that answer because this person had studied that topic, but almost couldn't even hear, couldn't perceive a question that wasn't essentially right off an exam.

These are the ones who depress me a little, because they have clearly done everything everyone told them to do (study hard, do well on tests, etc) and must have some significant raw intelligence to be able to do this well on a challenging curriculum... yet, for all that, they have walked away with so very little useful knowledge or skills. I also feel some anger at the system that they have learned too well to navigate... but by the time they get to me, it's too late to change anything.

I comfort myself in the near-sure knowledge they will find a job somewhere. Some percentage of them will even adapt to the real world and perhaps they will become great programmers. I don't know. I can't know. That's life.

But I can't in good conscience give a thumbs up for them. We are willing to train solid developers and we have a track record of hiring people that don't even know the language they will be working in (since they have demonstrated the ability to learn languages in the past), but you can only take that so far.

On the other hand, those who sat in college for four+ years and know neither the curriculum, nor any other skills, just barely squeaking by with the necessary grades and forgetting everything as soon as the class is over, well, they had every chance to realize they were in trouble and didn't take it. I don't feel depressed about them at all. That such people exist is just a fact of life.

jmonegro• 17 years ago

Heck, I can do all of that and I'm nowhere near a "senior developer"

Ask YC: Does interviewing developers leave you depressed?

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