The interview process began with a reasonably tricky Hackerrank challenge which was to be completed in around 75 minutes. After successfully completing this stage, I was advanced to a behavioural phone screen which was a short ~20-30 minute phone call with a recruiter about my resumé and talking a little bit about what I liked about my past jobs. Here they are trying to see if you are the right culture fit and have the correct motivation for wanting to work at Palantir. The third stage was a phone technical interview using Hackerrank Codepair. The task took around 1 hour and was a relatively average task - an interface was defined and you had to implement the methods. After this stage is the on-site - this was a painful 5.5 hour day at their office with 4 back-to-back interviews followed by lunch with an engineer (which I was told wasn't part of the assessment, but you never know). The interviews covered a range of things from 'Decomp', algorithms, system design, and data structures. After this, I was told I would hear back about the next stage in a few days. A week later I still heard nothing so sent a follow up and almost instantly found out I was rejected. Disappointing, but there was an opportunity for a short feedback call to find out what went wrong. I was told I could do most of the challenges but was just 'a little bit too slow'. Overall I did enjoy the hiring process, though it did drag on for many weeks, and at times communication could have been better, but on the whole everybody seemed well organised and competent.