Monzo Bank Backend Engineer Interview Questions
& Process

The interview started with an initial screening call to check if I was a good fit based on my past experiences. After that, there was a pair coding round which I passed without issues. The next stage was system design. I thought I did well, but it turned out I failed without any explanation. Interestingly, I even used Gemini to review my design and compare it with what might be expected, and Gemini indicated my design was superior and fulfilled the same requirements as a sliding window aggregator pattern (similar to Flink). This suggests they have a specific, predetermined answer and expect that exact design, which felt like a red flag, especially for a company that seems unaware of what a proper system design interview entails.

I applied for a Backend Engineer role at Monzo, which was remote. The first step was a recruiter call, which didn't need any prep. Then, there was an interview about a project I'd worked on and my specific contributions, where I had to explain my tech choices but without direct coding questions. For the third stage, I chose a pair programming interview over a take-home assignment because I didn't have the time. This went well, and I felt I communicated my ideas effectively. The final stage was supposed to be a 2-hour block with two interviews: system design and behavioral. However, the system design interview was canceled 15 minutes before it was supposed to start and then rescheduled, only to be canceled again the next day, and I received a rejection stating they were looking for more 'leader minded' individuals. The behavioral interview, which went ahead instead, was a bit odd, with one interviewer repeatedly mentioning their past experience at Google and Amazon, which felt a bit off-topic. I left that interview feeling unsure about Monzo but confident I did well. I was applying for L30, a mid-level position. It was disappointing to be rejected after preparing for two weeks for the system design interview and never getting the chance to do it. Overall, the interview wasn't technically hard, but I don't think it was a good fit. It did make me appreciate my current job's low-ego environment more.

The interview process was pretty open, and my recruiter was super helpful. They actually have a detailed blog post about the whole thing to help people understand it better, which I'd recommend checking out. I unfortunately didn't make it past the Systems Design round because I don't have a lot of experience in that area and didn't have enough time to prep. It was a good experience overall, but it was a bummer that even though I asked for feedback and my recruiter said she'd get it, I never actually received any despite following up.