Phone screen, remote algorithms & data structures coding challenge, demo project. Appealing position and company on paper, but the hiring process was a mess. Slow responses to emails, during the code challenge I was given feedback that was factually erroneous and would have led me astray had I not ignored it, and the demo project was dismissed with no feedback. Bad experience. Not entirely a waste of time—it taught me to pass on jobs that have you build something unless it's well-specified or they have a policy of providing feedback on it.