I applied through a recruiter. The process took 2 weeks.

The interview process consisted of a take-home technical challenge and two interview rounds. I also asked to have an extra phone call with the hiring manager prior to making a decision. Overall, my interview experience was positive. The take-home challenge was interesting and not excessively long. I had one technical interview where we went over the challenge, and another technical interview that was more focused on systems architecture and design. The process overall felt reasonably quick considering that Monzo is quite a large, well-known company. Bearing in mind that I was interviewing for a contract role, I would assume that the interview process for permanent roles might be longer. The hiring manager I spoke to gave me a good impression of themself and the team. Ultimately, the only reason I didn't accept the offer was because I received a permanent offer which worked out better overall than the day rate offered by Monzo. I knew their budget upfront, so I don't feel like they were trying to lowball me.

They asked me to design a high-level architecture for a system on a whiteboard.