I contacted them by email and got an interview. I did not pass the first interview, which was for 30 minutes. As far as I know, the interview process consists of four interviews.
They asked about concurrency and other things that I don't remember.
The following metrics were computed from 45 interview experiences for the Monzo Backend Engineer role.
Monzo's interview process for their Backend Engineer roles is very selective, failing most engineers who go through it.
Candidates reported having good feelings for Monzo's Backend Engineer interview process.