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

The first call was quite nice. It was a really pleasant chat with a current engineer about current and previous experience, some details, and a deep dive into technicalities. They were open to telling me about plans for expansion and what it is like to work at Monzo.

Then there is a tech test, which is kind of obsolete. This part made me feel like it is skewed towards more junior engineering roles. Everything they wanted to check was the deliverable product to the potential users. The interviewer glanced over technical parts where there could have been discussion points, and focused on asking what makes it a great product and why I chose not to focus on extra parts, such as displaying errors to the users in case of network issues. The call was never unpleasant, but I realized early that the decision was already made. Expressing it with an analogy, it felt like they were rating and considering exclusively how well an animal can swim, and it didn't matter if that was a fish or a dog.

Finish this project if it had to be released.

It was mostly about the details that were out of scope but implicit in a good product.