Wow, that was a very hard interview. For reference, I am a new graduate, not interviewing for a senior-level position. I was interviewing for a role that was listed as mostly HTML, CSS, and some JavaScript.

The initial phone interview went fine, as did the first Skype interview (the technical interview). I will go into the coding questions in detail below for your benefit.

I signed an NDA, so I cannot tell you the questions specifically, but I can offer advice. They require you to write fully working and tested code for non-trivial problems on the spot, in under an hour, with an interviewer closely observing.

The first question involved file parsing and file system operations (reading/writing files, etc.). It also required recursion and a stack, in addition to fundamental knowledge of your preferred language. I would definitely recommend using a high-level language like Python or Ruby because you simply don't have time to set up anything object-oriented. This question went well for me, and I finished ahead of schedule.

Next was a question involving a lot of logic. It required you to really think through the problem on paper and draw diagrams. It didn't require any special algorithms but demanded pretty good logic and thinking skills, along with a knowledge of modular arithmetic. You don't have time to try multiple approaches to the problem, so you have to get it right the first time. This one went pretty rough for me, as I couldn't conceptualize the entire program and approach before I started coding, and I ended up hitting some roadblocks. I finished right on time but was pretty rushed. Again, Python or Ruby (and taking full advantage of their high-level features) would be a great choice, as anything else would simply take too long.

Next was something web-based. Definitely know JavaScript/jQuery like the back of your hand, and practice coding some simple web apps from scratch in HTML, CSS, and JavaScript in under an hour. What tripped me up here was a particular feature of the DOM that I was unfamiliar with. I had to do two Google searches for syntax and to see what the return value of a function was (so I could use the result), which didn't seem to please the interviewer. I finished in time, and the application was 100% functional, but my solution was not the most elegant as I was pretty rushed in the last 10 minutes.

At this point, they stopped the interview and told me it wasn't going to work out, but they thanked me for coming. It's worth noting that I successfully solved all their questions within the allotted time, and they still stopped the interview halfway and gave me the bad news. They weren't just looking for you to solve the problems; they were looking for you to have a good, elegant solution with as little help as possible and in as little time as possible.

I was also surprised that a position advertised as front-end had such classical programming questions for interviews. The third question was more what I expected. I was also surprised that they required you to write tests for all your code. They were very concerned with edge cases (even way beyond the practical application of the code you were writing) and testing. You would think that in an interview where time is so limited, they would forgive those things and mostly test your general skills instead of your ability to make a truly fully functional and tested application.

See the above description for questions.