Stack Overflow Web Developer interview questions

Long interview process. It took almost one month to get a reply for my application, and then another month to do the interviews. I was interviewed 5 times on Google Hangouts, by different people - all very nice and kind. Each interview was split into 4 parts: quick talk about the job, quick talk about my skills and past experiences, code screen and Q&A about the company. I was expecting really hard code screens, but it turned out that they weren't that difficult. After the 5th interview I was somewhat confident that I was doing well, but then I got the rejection email. Hard to tell what exactly went wrong since it was a sort of canned response.