I had an initial phonecall with a member of the Instant Impact team (in my case, Tayla) and then a video interview with her, which was actually fairly similar to the rest of the 1-to-1 interviews I ended up doing for the role.
After this, I was sent a numerical and verbal reasoning test, which can be kind of tricky but if you do some studying before taking it you should be alright.
Then I was invited to the Octopus Discovery Day, which was around 3 hours long. It consisted of an icebreaker debate, then a customer service task in a team of 3, then a research-based task in a different team of 3. After this, there's a Q&A session with Octopus employees and a 1-to-1 interview, both lasting around 30 mins each.
After that, there was a final stage interview with two members of the Octopus team.
Overall, while the process was very thorough, it went to show how seriously Octopus take their recruitment and I feel like as a result I really earned my job offer.
Also, huge thanks to Tayla from Instant Impact. She has such positive energy and really did a lot of work in getting details and helping me with every step of the process.