First round is a Hackerrank with 4 questions, two of them emphasized math. Second round is a phone interview, LC med. After that, the recruiter calls you and even then, the hiring manager has to decide whether or not they want to move forward to the onsite. I don't know any other company that does this...most companies are: you made it past the last two rounds, so you can move on to the onsite. Not IXL. I've known multiple people who aced technical interviews, only to get rejected at this round. Why would waste other people's time? Onsite is 4 hours. 3 technical rounds, one behavioral. Expect LC med-hard. Honestly, for a company that does edtech, they have, for some reason, a "high" hiring bar. I can't imagine why, as I'm sure all you would be doing is some basic CRUD app for middle schoolers...