A total of 4 interviews over 3 weeks. No interview with HR, application went straight to the Quant team.
1st interview was about projects I've been working on and opportunity to ask questions about the company.
2nd interview was a technical task - 90 minutes to complete a coding challenge (time was not enough but that was part of the challenge) followed by an opportunity to talk about the approach.
3rd interview was more technical - not too many details but general ML questions. Was asked about XGBoost, Transformer models, hypermeter tuning among others.
4th and final interview was with head of Quant team - informal with one logical puzzle.
Followed an offer. Unfortunately, the salary range of Move Digital was literally half the ranges of similar positions in Sofia, so I picked a competing offer. Would have been nice to discuss that before going through four interviews. But I enjoyed the interviews even though they were ultimately fruitless.