Before the first technical interview recruiter shared with me the list of topics on data structures and algorithm development that could be relevant for the interview. In the beginning of the interview the interviewer asked me about how hash tables work and asked me to describe in more details hash functions and why hash collision happens (very weird questions for an ML position). After that a coding task where .json data should have been processed was shown and it had nothing to do with algorithms/data structures that are usually a part of such a test. It was just a pure (and a bit boring and tedious) data processing where fields should be extracted, converted, regrouped, etc. The task was not hard but it was easy to make mistake among many fields' transformations and aggregations.