The interview was rather nice - there were some questions about previous experience and projects, some specifics of algorithms used in this projects. Then we've talked about test-case that they gave me related to rec-sys before the interview - despite the fact that I didn't finish it, we've talked through all the details of my progress. There was also a small coding problem related to simple algorithm for sparse operations, which more less about ML and just on general algorithmic thinking. The only problem I had and it is crucial is that despite job title was "ML-engineer in RecSys", the questions and test-case were only about DL, and in fact after the intewview I figured out that they actually were looking for DL researcher in relation to rec-sys, not ML specialist.