I went through triplebyte. I was a little under the impression that going through there, you skip to the final interview. Which is true, but I thought the final interview was the final, final fit-type interview. Instead I got treated to a literal eight hour slog of whiteboard leetcode-style questions with a system design question and a twenty minute lunch in between. Really an incredibly exhausting week of interviews, though some weren't as harsh as I described above, they were with small startups who had coding problems but seemed more interested in culture fit.
for feedback to anyone at triplebyte reading this: had a chance to chat with multiple companies, many of them thought triplebyte was just an online coding quiz then off to on sites. I'm sure management-type people knew the process was more involved, but the lower-level? people definitely seemed dubious about triplebyte's value.