I emailed one of the recruiters to express my interest in a summer internship. She got back to me shortly to set up a phone call. On the phone, we just talked about what I was looking for in an internship, my experiences, and what the interview processes would look like at Thumbtack. She then emailed me a coding challenge, which was to implement a simple database. I submitted the code and heard back about a week later saying that I wouldn't be moving on with the processes.
For those interested, the recruiter informed me that after this coding challenge, there would be a video interview with an engineer, where I presume there would be a couple more programming and technical questions. Finally, there would be an on campus interview.