There is a lot of good intentions behind Github's process. They don't fall for the leetcode-style interviews that you see everywhere now. They've opted for a real-world problem instead, which is a lot more interesting and fun to work on. But unfortunately the execution is not great. They are very disorganized. Having to re-schedule meetings, not getting back to candidates in due time, etc.
Everyone was very nice, but the interviewers all seemed very junior, and not able to comprehend some of the concepts and tradeoffs being discussed during the interview. Once the interview was done, I just got ghosted for over a month now. I thought I did well, and for the first two weeks I've waited to receive feedback, after that I just considered that I wasn't selected. But they never replied to any of my followup emails, just radio silence.