Submit a CV/Cover Letter, and following this you'll be arranged a set of video interview questions (two of which are simple numerical ones at the level of A-level- you won't be asked anything nasty.) After the digital portion, you'll get a 1.5 hour interview- three presentations (personal, technical about your own project, then about one of their technologies.) The three interviewers were quite nice and speaking candidly was fine in instances- I didn't feel as though it was excessively formal. My advice would be to really research your chosen topic- I spent two days researching mine and knowing the physics background really helped (given that two of the interviewers were physics-oriented.) Also, one more bit of advice- on your "Technical Talk" about your own chosen previous project, make it very very generalist- I misunderstood this bit and made assumptions on the level to which it should be given that I shouldn't have. They don't want to know the details of how you carried out the analysis itself, propagated errors, etc etc- just the rough outline of the project as if explained to layman audiences. The questions will be where that'll pop up more in detail. Good luck!