Gitlab also will not negotiate on salary at all. I got through to the final round of interviews (round 6 of 7) and then HR let me know they'd changed how they calculated salary for my location, it dropped by $10k. I had wasted my time because at that point the salary was just too far below what I needed, even though I badly wanted to work there.
I was really interested in applying recently, until I saw what their interview process entails, and laughed. I can understand "hire slow", but 7 rounds of interviews is way too much to ask of candidates, and indicates a navel gazing culture I want no part of.