I applied and received a HackerRank challenge. The HackerRank question consisted of only one question.

I did not get the question right because the timer was running out. I got all the test cases right except one; had I had 5 minutes more, I would have fixed that.

While I am not into competitive programming (which is what HackerRank tests), I failed because I did not read the question and spent 40 minutes doing useless things. My advice is to spend some time READING the question.

Unfortunately, Palantir has decided that it is best for them to evaluate only candidates who pass that coding test. In my opinion, it is not a good filter, since I found out that I could have simply Googled the name of the coding challenge (which was "Catching an insider trader") and would have found a GitHub repo with the code for the challenge. You just tweak it a bit in a way HackerRank does not catch you, and you get a phone interview.

Catching an insider trader.

Pretty easy problem. You can solve it with two hash tables and a banal sorting procedure.