The first stage is a video interview where the candidate is asked a few questions. These questions are related to bp's values. This is the hardest in my opinion, but more practice should do you fine. The second stage is a technical interview with a staff data scientist at bp London, where the questions are about a case study using data (e.g. how would you collect the data, what statistical model and tests to use, how to visualise the data, etc). In general, think like a data scientist and a client-facing consultant. My interview was quite pleasant and it was easily one of the best interview experiences. The final stage is a team building exercise, whereby candidates are assigned to teams to solve some puzzles based on clues and common cipher techniques (e.g. Caesar's cipher, codes). Then, each candidate would write a short essay based on a case study (choosing the top 2 out of 6 projects to prioritise), then finally discuss with their teammates.