Worst interview experience ever. After the initial recruiter call, they sent me a link to a hackerrank test. The question in the OA was very poorly worded. They did not explain what certain terms meant. Sample test cases did not help obviously. I had to use my assumption in coding the solution. Obviously some test cases failed, indicating that my original assumption (of what the question meant btw) was wrong. Still, fair enough. Now the test cases which failed were "locked", aimed at "testing if your code can handle all scenarios, including corner cases". For the locked test cases, you're not allowed to view the input and even the expected output. They just tell you what your code output was, and that it was wrong. You're allowed to use debug statements to try and figure what went wrong, but when I used debug statements in my code, Hackerrank had a word limit on the debug output, so the debug output could never reach the point where the code could error and print a meaningful statement for me (because the input was supposedly too big). So basically, if you've seen the question before, better mug up the solution and vomit it out on the screen, or else you're never going to figure out why you're wrong. This might just be Hackerrank and not TuSimple's fault really, but if you're not going to invest in making someone's life easy BEFORE they join your company, then you're not going to make it after they've joined you.