1st week, a phone call from tech lead, basically saying hello to each other.
2nd week, a onsite culture fit interview, 3 tech people talking about your daily life, your interest, blah, blah ...
3rd week, a onsite code challenge about 3 hours. It's restful api app, require some concurrency pattern design. simple project, but not a lot of time. You have to setup your computer which is a fresh mac, setup golang env, and setup your editor whatever you like, which would take about 1 hour. Then do your research, yeah you can google whatever you need, and build and test, make sure it's working, then commit it back. If you write unit test cases, there will be some bonus point. ( My code is working perfectly, but i don't really have time to write any unit test ).
Overall, seems a very passionate tech team, the atmosphere is very good. Computers are fast, however the internet speed doesn't behave very well. I experienced frequently wireless connection drop during the code challenge.
4th week, there will be an onsite CEO meetup, I didn't get to this round, cause the recruiter told me the decision maker won't reach my salary range.
As a review, the overall interview process is not bad. However, I think 1st round, and 2nd can be combined into 1, with some tech questions. The onsite code challenge, can leave to candidate for homework, no only the code will done better, you can leave more creative room. Usually, a creative room is another important part of a code challenge.