More on Hiring Software Developers

http://hesh.am/2014/02/more-on-hiring-software-developers/

by HeshamMegid • 12 years ago

31 45 12 years ago

Seems to me like, you may not be as good as you think. If throwing a RSS feed at throws you then how you going to deal with real life legacy(sometimes not so legacy) crazyness?

r-s• 12 years ago

While this may be true, the guy who has worked a bunch with RSS feeds will ace this question even if he is a substantially worse developer. This wouldn't be a problem if said technology was what the company actually used, but in this case it was not.

arethuza• 12 years ago

Wouldn't you expect someone who had never seen or heard of RSS before to be able to do a bit of research, find out what it is and work out how to parse and give an account of the steps they took?

A good candidate who had never seen RSS before might be better at that than someone who has spent their entire career processing RSS and never thinking about the details.

johnnyfaehell3• 12 years ago

We're talking about XML basically. So he would have had to deal with the data in JSON if he had access to their API or XML in the test. Traversing XML isn't exactly the hardest thing to figure out and it took him an extra 100 minutes or so to figure it out. I personally consider the ability to learn one of the key things needed in a developer as you're constantly having to learn new things to achieve things you've never done before.

ronaldx2• 12 years ago

You seem to have missed the point.

Consider the following two developers. Who would you rather hire, and who will get hired under this system?

1. Developer completes the task, unfamiliar to them, in 2 hours, or

2. Developer completes the task, familiar to them, in 1.5 hours?

ricardobeat2• 12 years ago

Maybe I'm biased (no Objective-C experience), but in the platforms I work with this is a 15-minute task, so I wouldn't hire either. There is nothing extraordinary about being familiar with XML or regular expressions.

lucasnemeth2• 12 years ago

But if the only reason they hired someone else was because of speed, it seems really unreasonable. If he needed to spend 30 minutes reading about RSS and did a good job in the end, it really doesn't matter if he spend a little more time.

invalidOrTaken• 12 years ago

Fairly easily? If you're maintaining legacy code, here's what happens: you dive in, are horribly confused, and figure it out. Aaaaaaand...now you know it. Who cares if it took you three days to figure it out? You're going to be maintaining that codebase for a long time, aren't you?

We're kidding ourselves if we believe that our dev work is "all-new algorithms, all the time." It's not.

johnnyfaehell3• 12 years ago

Who cares? Stakeholders who are pissed of the legacy system isn't working and want it fixed now. If it's legacy and you're changing it, it's generally because it's broken and someone finally noticed.

jheriko• 12 years ago

"I took me 2 hours to figure out how to parse the RSS feed, extract the data I need using regex (since it was all inside a single tag) and present it in a table view."

i hate to be negative or damning in anyway - you make many valid points. however what you did there is an awful performance imo. i suspect it comes from living in web circles too much. i mean... you used a regex? this is one of the rare cases where i would write a c program with old fashioned procedural logic and expect it to be done much faster and to a higher quality.

also yes, good programmers perform very well in unfamiliar environments. not having the api you want is a common real world problem - learning new apis on the fly is a vital developer skill. the idea of an unfamiliar api should neither be daunting or challenging - unless it is of exceptionally poor quality (poor naming, no docs, no samples you must reverse engineer everything - but that shouldn't stop you either).

also, i hear a lot about the value of regexes - be careful, this is a web centric view. regexes are a very limited parsing/recognition tool and outside of web development - they go unused for most such problems - they either aren't powerful enough or add a needless layer of complexity in the general case.

as a concrete example most compiler generators will use regex for lexing but not for parsing at all - even repeated regex on a tokenised one line string is nowhere near as useful or practical as ll, lalr or especially glr parsing.

they also add a layer of complexity... someone famously said something like "oh, you used a regex... now you have /two/ problems"

good luck though. given more time and practice you will learn to eat these interviews up then spit them out with you rejecting them for making a poor first impression on you as a prospective employer... interviews work both ways after all.

thezoid3• 12 years ago

Let's throw you into a high stress environment give you data you've never worked with before and on top of that, just for funzies throw some namespaced SOAP at you. Oh and here's the WSDL, we want you to use that too, no parsing it on your own by hand.

A lot of people don't parse XML as much anymore. Most API providers have moved over serving up JSON and pretty much ask developers to only use that API.

Also this company fucked up. So you can't provide access to an API, but here read this RSS feed instead of something like serving up a static JSON file from a server somewhere.

As for the regex there's shipping, and there's doing it right. For all we know, they had to have it done before the 2 hours were up so they cut corners and got it done within the time requirement.

ricardobeat2• 12 years ago

Reading a XML feed instead of JSON is not comparable in difficulty to your examples at all. Getting XML parsed is not rocket science, just use a library. That was probably not the hardest part of the problem.

We have no idea where the expectation of working with their JSON API on the interview came from, the RSS feed could be their standard test problem. They didn't "fuck up", I'd even say their filter (reasonable or not) is working as intended.

Xdes• 12 years ago

i mean... you used a regex?

That was my initial impression, but after I reread the sentence I interpreted it as he used an RSS parser to get to the element with the data and then used a regex to extract the information from the data.

He didn't specify how the data was formatted inside the RSS element which leaves me to believe it might be something custom and not a simple CSV. This would be a perfectly valid use case for a regex.

vonmoltke4• 12 years ago

i hate to be negative or damning in anyway - you make many valid points. however what you did there is an awful performance imo. i suspect it comes from living in web circles too much. i mean... you used a regex? this is one of the rare cases where i would write a c program with old fashioned procedural logic and expect it to be done much faster and to a higher quality.

You were able to come to these conclusions with no knowledge of the content of the data stream, just assumptions?

also yes, good programmers perform very well in unfamiliar environments.

I think your definition of "good programmer" is nearing unicorn territory.

not having the api you want is a common real world problem - learning new apis on the fly is a vital developer skill. the idea of an unfamiliar api should neither be daunting or challenging - unless it is of exceptionally poor quality (poor naming, no docs, no samples you must reverse engineer everything - but that shouldn't stop you either).

By the sound of it, there was no API here. He was thrown a raw RSS feed and had to figure out what was in it and how to extract the relevant information.

also, i hear a lot about the value of regexes - be careful, this is a web centric view. regexes are a very limited parsing/recognition tool and outside of web development - they go unused for most such problems - they either aren't powerful enough or add a needless layer of complexity in the general case.

NLP makes heavy use of regexes for tasks where GLR parsers are overkill or where we have to fix character encoding or other such data noise.

good luck though. given more time and practice you will learn to eat these interviews up then spit them out with you rejecting them for making a poor first impression on you as a prospective employer... interviews work both ways after all.

Exactly what we need to do, teach to the test. That will keep interviews effective.

cema4• 12 years ago

  teach to the test

Yeah. At some point the candidate will become a professional candidate. I would rather stay a professional developer instead.

scrabble• 12 years ago

I had to do a pretty similar task in the interview process to land my current role. They provided me with an example of a poorly written program to parse the RSS feed.

Their example was using regex to parse. The first thing I did was rip it out. I think knowing when to use regex and when not to use it is a valuable skill.

Aqueous• 12 years ago

If the data was formatted like this:

<outer><inner>1</inner></outer><outer><inner>Content: This is some random content. Value: 500 SomethingElse: 23423</inner></outer>

and the problem was to extract the value, the somethingelse and the content, then a regex using extractors would probably help a lot.

ronilan2• 12 years ago

It's like, really, totally, entirely, off-topic, but, like I heard, somewhere, that some companies, like might, may be using, sometime, the following puzzle in their hiring process:

Imagine a world in which:

1. A players hire only A players;

2. B players hire C players; and C players hire D players etc. all the way down to Z players.

Assume that:

1. The trickle-down effect from B to Z causes bozo explosions in companies.

2. Bozo explosions are bad.

3. No one knows what letter player they are.

Develop a computer vision algorithm to minimize the risk of a bozo explosion.

edit: puzzle concept source: https://www.goodreads.com/quotes/391717-steve-jobs-has-a-say...

thezoid3• 12 years ago

A players should work on pulling people in other categories into their category. If everyone works on making everybody better you can make the place better.

Rejecting people because they don't match your idea of an A player (I'm assuming 'perfection') is pretty narrow minded.

kabdib2• 12 years ago

I agree, it's narrow-minded.

But it's SURVIVAL.

The times I've had to work with mis-hires have been awful, miserable and very depressing times. Like, they made me not want to come into work.

I was once the "human grep" for the mis-hire that sat across the hall from me. Constant questions; apologetic questions, but continual and unrelenting and stupid questions. Q: "Where does this function get called?" Me: "Search for it, please." Q: "What are the arguments to function X?" Me: "Please go find the function and see." Every few minutes, for MONTHS. Nothing I did seemed to help; this person was simply addicted to asking people about stuff that was literally in front of their face. Management didn't help ("this person is doing negative work"). Pleading didn't help. Getting them to save up questions for an "on the hour" chat didn't help. I wound up leaving that job.

Should we help people in a lower "letter grade"? Yes, if they are teachable. Should we suffer? No.

The simplest thing to do: Hire people better than you are, in general. Really try to do that and you'll find that your company won't rot from within, and people will be happier and tend not to leave.

rcruzeiro• 12 years ago

Well said. For me, what companies should look for is potential. No one can know everything and you can either hope to find someone who knows exactly what you need or find someone capable and willing to learn. How do you find someone with potential? Don't just give them a problem to solve but work with them in solving the problem. See how their thought process is and how well can they communicate their assumptions about the problem at hand. Nod them in the right direction sometimes and see how they take it from there.

kelseyfrancis2• 12 years ago

If everyone works on making everybody better you can make the place better.

I totally agree with this, but it requires active participation on everyone's part. It only works when people want to learn and actually want to produce high quality work. Many people don't seem to have any desire to improve their output. How do you fix a person's work ethic?

cema4• 12 years ago

I think you have a great point. But I would like to see a world where it happens the way you described it.

ap22213• 12 years ago

You lost me on the computer vision algorithm part.

ronilan2• 12 years ago

Use self.lookAlike(); It is a global method ;)

hkarthik• 12 years ago

I've heard this a lot. And usually the people espousing such hiring practices are C players when it comes to management.

While it sounds really good in theory, I think it's very difficult to discern an A player from a B player without letting biases get in the way (college attended, degree attained, GPA, etc).

Generally, I advise people to find what works for them, build a team that has consensus on hiring practices, and stick with it. But just because you found something that you think works, doesn't mean you've built a team of A players.

fhars• 12 years ago

That will solve itself once all the B players retire.

cema4• 12 years ago

So who hires the B players?

marcosero• 12 years ago

Parsing XML with a regex? I see why you have been immediately rejected

vonmoltke4• 12 years ago

He specifically said "since it was all inside a single tag". Without knowing what the payload of the tag is, its hard to say if regex was appropriate or not.

kelseyfrancis2• 12 years ago

its hard to say if regex was appropriate or not

I'd say it's never appropriate to parse XML with a regex. Even if you're just looking for something "inside a single tag", there are just too many gotchas like entities, CDATA sections, etc. Why bother with (or forget) any of that when there are well-tested XML libraries for probably every language, and many languages have it in their standard library.

rickyc091• 12 years ago

"That particular company’s APIs use JSON but they can’t give me access to the APIs, which I do understand. So instead I was given a URL to an RSS feed to work with. While that makes the task a bit harder for me since I never had to parse RSS feeds before, it also makes it even more pointless."

The company could have just as easily saved a copy of the results from the private JSON api.

trustfundbaby• 12 years ago

Small piece of advice: Sometimes you get rejected from interviews for what seems like silly reasons, and most of the time they are really stupid. But always remember there is someone out there that would have gone into that interview, and completely blown their minds, even if they'd asked them to complete the task blindfolded in Scala. Make it your goal in life to be that person.

More on Hiring Software Developers

Related Stories