The interview process began with a short phone conversation with the recruiter, followed by an hour-long HackerRank exercise.

Next, there was an hour-long phone screen over Skype, which included a Codepad assessment.

Finally, I flew to their office in San Francisco for a final round consisting of four 1-hour interviews. Dropbox covered the flight and accommodation costs. There was also free lunch and a presentation halfway through the set of interviews. Overall, it was an enjoyable experience.

Design an ID allocator which can allocate and de-allocate from a range of 1-1,000,000.