The interview process consisted of the following stages:

• Phone call with a recruiter to discuss Palantir and potential roles.
• Technical phone screen with an engineer.
• Phone call with a different recruiter to discuss the on-site interview and choose between General Engineer or Systems Engineer tracks.
• On-site interview: breakfast, three interviews, lunch, a demo, and then sent home.
• Rejection email stating I was "not a strong enough fit."

Overall, the process went smoothly. What bothered me was that I felt I performed very well during the on-site interviews. All problems were solved with good solutions that received very positive feedback from the interviewers. After the demo, I was ready to continue with more interviews, but was instead told to go home. I then received a one-line email stating I was not a strong enough fit. I spent a week reviewing each interview and could not identify any areas where I had faltered. My friends, whom I consulted, also agreed that it didn't seem like I had performed poorly. There is no clear reason for rejection after receiving only positive feedback and no explanation.

The phone interview question was about matching parentheses.

I signed an NDA for the onsite interviews.