I attended an online assessment centre which included a presentation, interview and group work. The presentation was showing your most important piece of academic work you had done (so in my case i did my dissertation) and the individual interview was a technical interview - each for 15 mins.

More personal than other grad scheme interviews, asked for my most significant piece of work/learning so far. (Think Diss, group project or other big pieces ideally) Obviously requires clearance interview too which was very personal but nothing to be concerned about.