For the first round, they gave me a take home exercise of building a machine learning model. However, for the second round, they did not indicate me the interview was onsite (but I am not live in Pittsburgh). In the email, the recruiter only gave me a link to schedule a interview time, and did not reply my follow-up emails. So I was waiting for the phone call and no one reached out me. My friend who referred me helped me to ask the recruiters and they finally found I am not at Pittsburgh. And I even can feel the recruiters though this was my fault to not reach out them I am not at Pittsburgh. Besides, the company does not want to cover the traveling fee for my onsite interview. In the end, they did not reschedule my interview. To be honest, I guess this is my worst interview experience ever.