I applied for this position online and received a Hackerrank challenge (ML, SQL, coding in 90 minutes) in 10 days. It took another week or so for them to get back and schedule a time to talk with the recruiter. I was told in the middle of the phone screening that they want someone that could start ASAP and with more working experience. They can easily get that information from my resume before sending over Hackerrank, but they decided to waste applicants' time.

Pretty simple, applied online and got a hackerank challenge. Challenge mostly consists of basic probability, machine learning mcqs and one coding question. Study some basic concepts of data mining and machine learning.