IXL Learning Software Engineer interview questions

Standard initial phone interview with basic behavioral and background questions. After that I was given an online assessment test on HackerRank consisting of 4 questions in 90 minutes. The questions themselves weren't too challenging but given the time limit, it was definitely a rush to answer and properly test all of them. I won't reveal the specific questions, but I did find some of them to be strange. One of them required knowing a somewhat obscure and specific mathematical algorithm to solve efficiently. I did not know it and gave a sub-optimal answer. In general, I find that using an OAT is a sub-par way to conduct an initial screen. People can quite easily use Google to answer the questions or learn the algorithms, which puts the ones taking the test honestly at a disadvantage. Given my experience, and the many other similar reviews posted here, I would advise IXL to rethink their interview process. It sounds like a great company, but interview process was definitely unusual.