Why? My experience with them was pretty bad. I took their assessment for web development, I think I even did an assignment, and got put on a video call with someone from Triplebyte. He never cracked a smile. Suddenly I got asked a bunch of CS questions that really were not very relevant to web development, some of which were entirely inappropriate like sorting a binary search tree. I even told the guy that I thought I was getting those questions wrong and he just scowled and said "well you just don't know when you're going to use this stuff." "My point exactly," I thought.
Ultimately I got rejected.
The whole idea that you can boil down a candidate to some coding challenges and a video quiz is bad. I do like the idea of streamlining the hiring process for developers, but there's more to it than knowing a bunch of stuff, because that can be gamed. And quizzing me on irrelevant material was a bad move. A firm like Triplebyte won't be as good at interviewing a candidate as the employer itself, and may even keep perfectly qualified candidates out of view from all employers affiliated with them.
I started using them about a year ago (first passively looking, then actively looking)
I really enjoyed the ability to be assessed on something besides Leetcode style questions.
I didn't take a job through their platform (though I did get one really strong offer), but even still, found the assessments incredibly useful, since they give you a percentile distribution of your performance for each topic-specific test.
After taking their assessments, when interviewers asked me how I am at, say, Python, I could tell them I have a hard time assessing my capabilities. "But hey, I took this standardized test that says I'm in the 85th percentile, not sure how good of a metric it is" (and not mentioning that I think I'm OK at best, at Python)
It's the only way I've found to get a measure of your talents compared to the rest of the field (even if it might not be reliable/useful)
A lot of the companies that interview through Triplebyte also skip LC mediums because they have a different signal about your potential suitability as a candidate.
Way too much of engineering is non-quantifiable. Putting a number to someone's skills is bound to be reductive at best.
Like honestly I might think I'm a 3 at X, but if some test that thousands of other people took tells me I'm in the 90th percentile of X users, that information is still useful to me.