Ask HN: Do interviewers expect this much expertise or am I that bad a programmer?

Interviewers sometimes make strict and complex tests to see how well you do under pressure. They give you brain teasers and other things as well.

Their test was written for Java before they contacted you for an interview. They think everyone knows Java, and that is not always the case.

Writing the code in an hour is very hard to do and follow all the guidelines as well. You'd have to have a photographic memory on Java and how messaging works.

They are quite clear that you can use the language you want (preferred = Java).

For a candidate with 5 years experience, if I was the interviewer, I would expect you to plow through this problem with ease, even on an awful whiteboard. The reason is that pub/sub is one of the systems that are quite important to know and understand for non-trivial enterprise applications. If you understand it well, you should have no problem in implementing a basic solution within an hour.

I'm a big proponent of the idea that one shouldn't have to prepare for an interview beyond the curiosity of what the potential future employer do and which technologies do they use.

Maybe you're really good at what you do and the question asked is too different from the kind of problems that you've been working on in the past few years. Are you good ? I don't know. I don't know you. Moreover, failing one interview does not answer that question for you. Neither is failing at 2 to N interviews...

The task description is pretty dumb. It claims to be language agnostic but it is not because very language has a completely different threading model which greatly affects how the task would be solved. Threading in Ruby is not at all like threading in Java.

I've written threading and worker queue code in Java so I can kind of "see" what solution they are aiming for. But they are specialized domains, so if you have mostly written web code, you won't have had any experience with them.

Never the less, if you work on this problem in Java and you write a thread-safe solution, you will become a better programmer for it.

This is a non-trivial problem, assuming they really do want this to be a network server. For instance, it did not specify if they wanted "at most once vs at least once" delivery specifications (I'm guessing they wanted to see if you have come across this). Dealing with reliability in the face of failing network connections takes some serious thought.

One thing I may have pushed back on is "the requirements say this should be thread safe, but it does not say it must use threading. Can the server be single threaded?". If they are ok with that, writing an async IO server in a language geared for it would make things a bit easier (Erlang, Go, Python + Gevent, Node, etc). If feeling cheeky, you could ask if you just write a basic server sitting in front of Redis or using 0mq since the specs did not explicitly disallow 3rd party libs or apps.

At the end of the day, this may be one of those problems where they see how far you get, and don't expect most candidates to finish in 60 mins. It could also just be not the best test question relevant to the job you were applying for. I think it's fair game for anyone w/ previous experience writing low level networking code and servers from scratch, which is generally not what PHP/Rails devs are doing.

If I were to write a trivial implementation from scratch then I would enjoy this type of question. If it is about writing code to interact with some specific Java messaging APIs then it's not a fair question to ask someone who doesn't have the specific skill set.

Seems a bit silly to me unless there was an understanding you were expected to have experience with this exact sort of problem. Probably someone just trying to be a badass.

I don;t think it is about the standard. It looks like they only want someone who has already worked with messaging servers. If you have not worked on that before, then you have nothing to worry. Sometimes it happens that what a company/group wants is not what you have to offer, even if you are a good programmer. With all the media hype regarding these unicorns, you feel let down. Shrug it off and move on to other companies.

Java is just to make their own life easier, because they readily know the Java solution.

I'd say this is a bit extreme, even for a programming interview test. I think it assumes you've already done something like it in the past. But then, if you haven't, then maybe you aren't a fit for this particular job.

I once interviewed at a game/graphics startup and they asked me to implement a non-trivial graphics algorithm in a take-home test. I completed it successfully, but only because I've done graphics programming for decades, and in fact had implemented this very algorithm just months before in a side project. Someone without experience in that specific area of graphics programming would probably not have passed.