I got an employee referral, and two weeks later, a phone interview was scheduled. I was asked to write some code on CollabEdit and answer some Unix questions related to process handling and regex.

Within a week, I heard from them and was invited for an on-site interview. I had four rounds of interviews, all one-to-one. I was asked a variety of questions, ranging from explaining the nature of my previous work experience and projects mentioned on my resume to object-oriented system concepts, algorithms related to binary trees, dynamic programming, and hash tables.

I was required to do white-board coding, but syntax wasn't the major concern as long as I could write pseudocode properly and explain it.

Things were very smooth until the on-site interview but moved slower after that. As is well known, the hiring process at Yahoo is quite bureaucratic. It took nearly four weeks after the on-site interview to hear about the final decision. Overall, however, the interview process was nice and smooth.

Given events with start and end times, merge all overlapping events with updated start and end times. The difficult part was optimization.