I went through Triplebyte and did very well with their code screen as I was at my home office with my ergonomic keyboard and 27" monitors - a comfortable setup.
After an Affinity phone screen I was invited to fly to SF for an all-day onsite. The people were all super friendly, and Ray - one of the founders - took the time to chat with me for an hour. He's driven and passionate (though you wouldn't know it at first glance).
The questions were about command-line string parsing, not about algorithms or graphs or abstract thinking. It was a "get it done, fast" kind of interview.
My feedback was that I was slower than other candidates. I was on my laptop with an Asian keyboard layout - I didn't practice typing on it before I flew there because I've always had an external 104-key ergonomic keyboard. Whoops. They value speed of coding, not comments and sanity check blocks. Even if you are an average coder, just code quickly!
Overall it was a positive process. Keep in mind they keep changing their office location as they grow. Also, if you don't get an offer, send them a few emails politely asking for interview feedback.