Started with hirevue where you record your answers to some questions. Took a long time to get back to me after that, then I had a technical interview on teams going over some SQL things with an engineer, very nice guy. Third round was a group interview virtual "exploration day" with hiring managers and recruiters. They told you more about bp, had you solve a puzzle thing with a group and discuss the viability of some green energy projects at BP with a group and individually to see your communication/teamwork. There were a few typos on their website and I think the answer key for the puzzle was incorrect, but not bad overall.
The salary/benefits were only discussed at the end of the interview process, the offer was pretty good but I'd suggest discussing it sooner in case expectations aren't matching for either side. Overall the process was pretty good but there's a few minor things that could be improved.