Initial email a few days after they receive your application, asking to take a HackerRank coding test. The test was 60 minutes, two questions (one coding, one essay question). Be prepared to answer these as quickly as possible, because 60 minutes is rushing it. If you fail the coding challenge, don't bother trying to reach out to them, you're done. They use JazzHR, and do not reply to emails at all. Absolute waste of an hour.