Technical interviews in the US compared to the UK

https://news.ycombinator.com/item?id=3369723

by peacemaker • 15 years ago

31 38 15 years ago

news.ycombinator.com

I've recently moved to the US from the UK and a few weeks ago put my resume out there looking for programming work. So far I've had 3 interviews with some of the 'bigger' names around and all 3 came as quite a shock.

Firstly, all the interviews have consisted of at least one highly technical phone screen - this is following a more relaxed (but still technical focused) interview with HR & management. If you get past those stages, you then have an entire days worth of technical interviews involving a lot of whiteboard coding. Most of the questions are completely irrelevant to real-world programming (reverse a linked list etc.) yet a lot of weight is put on the answers.

In the UK, this level of testing is rare in my experience. Instead more focus is put on your resume and achievements plus if your personality fits during the 1-2 hour in-person interview. You will get a technical test in most places but it is usually an hour or so and very job focussed.

My second problem is to do with attitude. We brits tend to remain rather modest of our achievements because boasting is considered in poor taste. I'm finding that attitude is really affecting the way American interviewers are judging me. It seems they expect interviewees to scream out loud that they are the greatest programmer the world has ever seen! Of course I'm not, but I am bloody good at what I do.

The strangest thing is, I get calls almost every day wanting to talk about interviews based upon my resume yet so far, no luck in breaking that cultural barrier that seems to exist.

I'm starting to adapt though and understanding the American way of doing things. I want to fit in here and have a successful career. If anyone wants to share some insights I'd be most grateful.

ig1• 15 years ago

I don't know where you've interviewed in the UK, but the type the of interviews you've described in the US are pretty much the standard in the UK at major tech companies and in the financial sector.

The purpose of questions such as reversing a linked list is to test your understanding of fairly fundamental computer science, to see if you're someone who understands the technology you're using or if you treat it as a black box. For more technical companies they need people who fall into the first category hence ask that type of question.

peacemaker9• 15 years ago

I completely understand the reasons why they ask the questions. I just don't think they work that well for finding out if a candidate would work out to be a good employee.

As for interviewing in the UK, I've interviewed at many large and small companies and yes, they do have technical tests but I have come across none so in depth as the ones I'm encountering over here.

The strangest thing though, all these places have loads of spaces open for programmers yet such a rigid system that seems to require 100% scoring that most programmers, regardless of how valuable they might be, end up being ignored. The worst is for someone like myself who has been out of university for so long I don't remember how to answer some of the very exam-like questions yet you give me a coding problem and I can solve it.

coffeenut• 15 years ago

The theory behind the technical questions is not whether you can reverse a linked list, but rather:

  -Do you know basic computer science concepts
  -How are your problem-solving skills
  -Can you move beyond "obvious, yet flawed" answers
  -Do you exhibit passion (passion to get to the right answer, enjoyment of problem solving, etc)
  -Can you present and justify solutions
  -Integrity (If you've seen the problem before, tell the interviewer, don't 'fake solve' it!)
  -Are you thorough (probing to understand problem, handling error cases, boundary cases, etc)
  -Can you communicate/collaborate with the interviewer

Anyway, that's the theory. In reality, many interviewers use whiteboard questions as a crutch to an easy interview loop and don't really understand why they're asking what they're asking.

My biggest piece of advice is to remember the technical interview isn't just (or even mostly) about the technical aspect. Communicate constantly, verbalize your thoughts, ask questions, show passion. I've hired plenty of people who have done not-so-well at the technical portion, and I've given a 'no hire' to plenty who have aced the technical portion.

peacemaker9• 15 years ago

Thanks for your input. I get most of the reasons you listed and feel that I do communicate well (I've been in charge of small teams/mentored etc.) and don't get flustered when asked these questions. But a lot of the time they require some kind of "leap" from the problem to the solution. Usually it's some obscure data structure I should have used or an adapted sorting algorithm which in my 10 years of developing software I've never had to use before - and I've worked in some diverse industries.

I've got another day long interview in a couple of days and to get there I had to do 2 phone screens and a 3-day long skills test at home. I get it, you have to get the right people but in a country where you can just sack someone at the drop of a hat it seems so over the top. Even more so in comparison to the UK where firing someone is extremely difficult.

16s• 15 years ago

You may "quit at the drop of a hat" as well so it works both ways. In the US, it's called "at will employment" so if you get stuck somewhere you don't like, you may leave. But if you want to use the company as a reference for future jobs, be nice to them and provide a few weeks notice, etc.

Kurtz792• 15 years ago

Hello, I´m European as well, and I often thought about doing something similar (i.e. moving to US for a period of time looking for work). I have already been in Silicon Valley for an internship (with a researcher visa) years ago and loved the place, but I always thought that getting a working Visa would be hard, since the company basically has to petition for your visa and pay all the associated legal expenses.

In your experience then, is it something that can be done (I guess so given that you had 3 interviews already).? Or do companies gives you a hard time if you don´t have a work permit to start with ?

Thanks.

peacemaker9• 15 years ago

Hey, well I've been married to an American citizen for 5 years before coming over here so I got my green card recently after applying about 6 months ago. Because I don't require any sort of sponsorship I think I have more opportunities than someone who does. I'm afraid I can't really say for sure if you will have a harder time trying to get interviews when requiring sponsorship, but my opinion would be that yes, you will find it more difficult.

Kurtz792• 15 years ago

Ah, that explains it :)

Thanks for the answer anyway...

trustfundbaby• 15 years ago

Yes it can be done, but its extremely tough if it is your first visa application (much easier to do a transfer). In that case you'd want the company to petition for you while you were interning (h1-b cap opens in April if I remember correctly) so that after your internship you could get approved and start in October (thats when you're allowed to start working).

The trick is to know all the ins and outs of the process (or get an experienced immigration attorney to advise you), so that if any issues come up you (preferably your attorney) can walk them through the process. It really isn't that hard, but not a lot of people bother to sit down and learn how to do it correctly.

The other thing is that if you can pay the associated costs on your own, then you can insulate the company from the process to a large degree ... I'm not sure that option is still available though, as I think it has been changed to require the company to pay all the fees on their own.

ekidd• 15 years ago

I've interviewed people in the US, and the first time I asked candidates to reverse a linked list, I was shocked by the results.

Candidate A had a long track record of success, at least on paper. He was obviously motivated, responsible, and likable. He had done a lot of hardware work, and claimed to be a decent (but not top-notch) C programmer.

Candidate B was straight out of college, and he had a weak résumé. We suspected that he had some coding talent, but he didn't have much experience, and we had no idea whether or not he was reliable.

We were leaning heavily towards candidate A. He interviewed brilliantly and seemed like a good fit. Then I asked him to reverse a linked list, and he responded, "Do you have a copy of K&R? I don't remember what kind of braces C uses for functions." After about 30 minutes, he was still trying and failing to find a solution.

When I asked the same question to candidate B, he shrugged, and wrote out a correct solution without stopping to think. So we hired candidate B, and he did excellent work for us for years.

And this is not a one-time incident. It's amazing how many people can bluff their way through an interview without knowing how to sum the numbers in an array. Résumés are full of lies, phone screens are hard to do well, and references are hand-picked by the candidate. So I'm a big believer in coding questions.

peacemaker9• 15 years ago

I also believe in coding questions but the linked list question in this situation wasn't a good one to use for both candidates.

Why? Well of course the kid straight out of university would answer a question on data structures correctly, he probably did the class for that only a few months prior.

In your example, Candidate A was obviously a no-hire after not even knowing what braces a C function uses but a lot of people similar to Candidate A who can actually code are being presented with questions about linked lists and similar structures no-one who has written code for years would remember, let alone use in their daily work lives.

I want to say again, I'm 100% for coding questions but I think they should reflect more on the type of work you need the candidate to do in the job rather than some academic examples you feel you must ask just because Microsoft/Amazon do.

ernestipark2• 15 years ago

I wouldn't consider reversing a linked list a data structures question, it's a coding question. Everyone knows what a linked list is and that you have to iterate through it and flip the "arrows". The tricky part is being able to maintain all the pointers and know how to order your operations and handle any edge cases. That's what questions like these are supposed to check for, can you actually articulate into code a solution that you understand on a high level in your head.

davidhansen• 15 years ago

but a lot of people similar to Candidate A who can actually code are being presented with questions about linked lists and similar structures no-one who has written code for years would remember, let alone use in their daily work lives.

Your reference to "remembering" is entirely irrelevant. What is relevant here is whether the candidate can reason through the problem - and more power to the candidate if s/he's been out of school for N years. What I strive for with technical questions is not to find out how well the candidate remembers their Knuth( although finding someone who actually read Knuth is nice ) - it is to determine how well they think through problems. And with no offense intended, if you can't at the very least come up with some ~3N complexity stupid-but-it-works stack-based solution to the problem of reversing a linked list, you probably shouldn't be a professional developer.

salsakran2• 15 years ago

I completely disagree. If you view data structures as something that you "remember" from your university days, then you are more of a "tool user" than a programmer. No matter what a candidate has managed to accomplish using their IDE and copy/paste adventures, if they can't reverse a linked list on the spot they are a blindingly obvious "no-hire".

This should be the sort of thing anyone looking for a programming job should be able to do as the programming equivalent of muscle memory.

phpguy2• 15 years ago

Ive laughed at these type of questions and told them "How 90's of you". Of course I work in a more entrepreneurial field where getting the job done is more important than fretting over a linked list. Just my two cents.

Peaker• 15 years ago

The linked list question is just a proxy for basic competence.

Without such basic competence, it is probably not possible get "the job done" well.

peacemaker9• 15 years ago

I can see where you're coming from, sometimes I'm half expecting them to ask me how I'd move mount fuji ;)

araneae2• 15 years ago

As someone moving from the U.S. (possibly) to London in a few years, that's actually pretty comforting. I'm mostly self taught so any hardcore CS problems will throw me. I CAN reverse a linked list, but only if it's a doubly linked list :). (Ok, kidding, I can reverse a singly linked list, but ask me what heapsort is and I would definitely have to look it up.)

froseph2• 15 years ago

This is precisely why they use reverse a linked list- it's common enough that everyone understands it, and if not, it can be quickly explained, and everyone understands that you 'just need to flip' the arrows, yet we get many people who don't get it.

froseph2• 15 years ago

For what it's worth I don't really care much about your resume other than the fact that it is a signal for if you _may_ be a good hire. My job as an interviewer is to test if you are a good hire and you need to be able to pass that test. I ask easy programmings questions as a smoke test of technical competence. I banter about your interests and past achievements to see if we are able to communicate and get along (as well as probe for bullshit). I ask hard problems to see how you think and your motivation to get the job done.

Having been in a big company, the primary reason we did lots of coding is to ensure that we have enough signal that you can code. One bombed interview may not mean much, but any more may be an indication that you cannot get the job done without some amount of babysitting.

tnuc2• 15 years ago

I don't think the original poster was questioning the interview process so much as pointing out the cultural differences that exist.

To say that not passing two interviews means he can't get the job done without babysitting is ignorant. Looking at most of the hiring posts on hn, it becomes very obvious that they want to do a cultural fit. Defining a cultural fit is going to differ depending on who you ask.

sgrove2• 15 years ago

I started replying, and it turned into a long story: http://trapm.com/how-to-get-hired-or-the-silly-but-adorable-...

peacemaker9• 15 years ago

Hey thanks for that, a good read. The part that stuck out the most for me was pushing questions back to the interviewers. I tend to do this naturally as well but I came about this method differently than you. I see interviews as a chance to sell myself to the company but almost and equally as important, for the company to sell itself to me. Mentally, I take the approach that I'm a good engineer and could work for many different companies so what can this company offer me? You can usually tell quite early on when interviewing with a company if they believe somehow that they're doing you a "favor" by even talking to you. I avoid those places like the plague.

sgrove2• 15 years ago

Yup, it's a really nice natural filter. If the companies don't feel comfortable doing themselves what they've asked you to do, you should probably duck out of there with a polite declination as quickly as possible.

tnuc2• 15 years ago

I find in the interviews that the Americans like to ask questions based on what you learnt in college. It's almost like a test on your university abilities. The tests on your ability to do the actual job seem to be rather scarce. Your ability to remember different sorting algorithms is much more important.

> It seems they expect interviewees to scream out loud that they are the greatest programmer the world has ever seen!

It is the American way to tell everyone how great you are and then once you have kids, you have to tell everyone how great they are. I suppose it is to be expected in what was/is a competitive capitalist market. If I interviewed in the UK and told everyone how great I am, it would be a sure fire way to not get the job.

Some US companies have a tendency to ask questions that are tricky or are obscure. Even worse is the interview that is completely overloaded with buzzwords and jargon.

SnoopDougieDoug• 15 years ago

Has anyone ever had to reverse a linked list in "the real world" (tm)? Is that a singly-linked or double-linked? Can I use Google, which is what any sane developer would do in "the real world". I don't remember squat about data structs 301. So what. What does the typical developer do daily? I would be much more interested in how they approach bugs. What approaches do they use? Any tools they carry on a flash drive? What drives them crazy? What do they love? What are they learning?

allenc• 15 years ago

As someone who does a lot of interviews and has switched jobs six months ago, I understand how it feels, on both sides. I've written my fair amount on the topics too (http://allenc.com/2011/04/how-to-score-a-google-onsite-inter... and http://corner.squareup.com/2011/10/why-we-pair-interview.htm...).

I think a part of it is ego, especially nowadays - some really good engineers are doing their own startups now, and when these companies start hiring they're looking for people just as good as they are, which means taking a page out of the Google/Facebook style interview process. I've met and worked with people who, while with great intentions, think great software engineering comes from graduate-level CS studies.

That said, resumes and achievements aren't great indicators of success because so many people have good-looking job histories and many can also sound good just talking about their experience. For me, front-end web eng. has become a pain to hire for; too many candidates put down things they don't know enough about, and unless they have fully-viewable source online it's hard to tell whether they accomplished much of anything in their past projects.

I do think our current standard of heavy whiteboard interviews is misleading, though, which is why I prefer pairing interviews when given a choice. Working with an engineer is a great way to measure cultural fit.

And finally, companies are super careful with filling a position because while firing someone is at-will, the cost in bringing that person up-to-speed, dealing with the bad player's code and work, the messiness in letting that person go (in planning, morale, etc.), not to mention salary and severance make everybody err on the side of caution.

roniburd• 15 years ago

If you can't spend 1-2 days revisiting old basic algorithms like this, you are not even self-motivated or capable of learning on the job to probably join the "bigger names" like you mention. Interviews like these test how well you are at basic comp. sci problems. I used to be like you and from a much more distant country but eventually I realized these questions have a lot of merit: if you don’t know these basics all you are capable of is gluing some APIs and solving some of integration/compatibility problems in different platforms. Not a good fit for companies who are creating those APIs, platforms and breaking new ground. Also, think about it from a statistics point of view: you are more likely to get false positive with people who can’t pass that simple question those who can.

wantrepreneur• 15 years ago

Bloody hell,one piece of advice-don't ever use "bloody good" or any other phrase with the word bloody in it.That's the real world,not a Harry Potter movie.Good luck!

Technical interviews in the US compared to the UK

Related Stories