30 minute call with the recruiter. Everything went well and it seemed I was a very good fit for the role until I mentioned I don't use Python in production at my current workplace. The recruiter was immediately concerned about that fact but I didn't think much about it. Got a rejection email after I followed up with them 2 days later. It mentioned that they were specifically looking for experience in Python. Quite odd given that data engineers usually have experience with one of Scala, Java or Python (and python is the easiest to learn), but what matters more is the candidate's knowledge about programming, data engg and dist sys.