The process took around a month. Reached out by the recruiter via LinkedIn. Took the Hacker rank challenge and passed 8/11 test cases. I am assuming they care more about the structure and your approach rather than the correctness. After that I had a phone call with recruiter, where she went over general behavioral questions followed by a technical phone interview with an engineer. The technical question was not bad, it was an easier form of UTF-8 encoding problem on leet code. Then I was invited to the onsite interview, which had 3 rounds: algorithms, system-design/open-ended, and debugging. The first round was a bit challenging, and I took a couple hints to come to the most efficient solution, which might have been why Palantir did not move forward with me. Second round was an open ended problem and the goal is to cover the problem in as much depth as possible, which was easy in my opinion. Third round was debugging and they try to see your approach and how accurately and efficiently you fix the bad part of the code.