A 30-minute phone call and a 60-minute technical interview. For the technical interview I was offered a choice of 3 technologies: SQL, pandas, or PySpark. There were 3 related hacker rank data aggregation questions. the data and questions were simple to do in SQL, but I chose pandas and had a hard time understanding the error messages

Tough interview, but well-supported. Initial talk with internal recruiter, coding test (fairly easy Leetcode style) and two hour-long, back to back technical interviews, one of which was a Palantir-specific learning type and the other of which was effectively systems design. Unfortunately I didn't make it past this point, but it would have been followed by a final round with a hiring manager. Everyone was very friendly and the company was fast and clear in their communications.