The interview process consisted of one online code challenge on CodeSignal, two phone interviews, and a final on-site interview. What set this process apart from other processes I've experienced was how the subject matter of the questions (especially on the online code challenge) were in some way relevant to what Thumbtack does.

After you apply, you'll be sent an online assessment. Mine was 2 questions, both string parsing. First one passed, second one was extremely involved and I didn't finish it, but still got through to the next round. Then a recruiter will reach out via email so you can schedule a technical interview. The interview is (I believe) 60 minutes, but may have been. 45, can't remember. You log onto a shared code pad, the interviewer describes the question, you code live while talking through it on the phone. Can choose pretty much any language. Must create your own input/test cases. You have whatever time is remaining to ask questions/talk to the interviewer.