Took an online assessment, multiple choice questions and one coding problem. Think I got most questions correct. For the coding problem, had a solution that worked but not fast enough for all test cases and ran out of time when optimizing. Two weeks later, received a call and email from the recruiter about my availability for an onsite interview. After both calling him back and leaving a voicemail, and also emailing him back. Never heard from him. Tried emailing and calling the next week to follow up again and still nothing. Just found it so confusing and unprofessional.