Technical phone screen followed by an onsite interview. I had a pretty terrible experience here. My onsite was with 4 technical team members: one manager and three engineers in total. Thumbtack really needs to screen its interviewers. I've been in the industry for about 8 years, and this is really something else.

I answered one question fully correctly, one question fully correctly with some Googling because I couldn't remember some API method names, did the system design without too much whiteboarding, and answered one last algorithm question that wasn't optimal.

One of the interviewers did not know the answer to the question that he himself asked me. I answered it completely, only to hear that he gave me negative feedback because I didn't know the names of a method. The funny thing is, he didn't know all 4 of the methods I was describing, nor did he know how to implement the question he was asking. It was apparent when I showed him my implementation, and he went, "Ah! That's how you do it!"

My last interviewer spoke in mumbles and barely spoke at all during the interview. When I asked clarifying questions, he'd look up from his laptop, bewildered. He gave no feedback as I was talking through approaches. Ultimately, he said to implement one of the ideas that I mentioned. Afterwards, his feedback was that I didn't use the optimal data structure.

But I haven't gotten to the worst part. In the beginning of one of the interviews, my interviewer said something along the lines of, "Thumbtack is trying to hire for more diversity. Too bad for us, huh?" followed by a smile and a wink.

Needless to say, I was absolutely appalled. Having another person to mediate the interview would be my best suggestion for Thumbtack. How are you so sure that your employees have the same goal as the company to hire the best if their preconceived notions get in the way?

Implement a calendar application that allows users to add events and throw an error if an event has an overlapping time with another.