Monzo Bank Backend Engineer interview questions

1. Recruiter call — short intro, they explain the role, you ask questions. Low stakes. 2. Initial call (1 hour) — this is the one to prepare hardest for. They've read your CV and want to go deep on a recent project: how it was built, what trade-offs you made, what you'd do differently. It's a conversation, not a quiz — but they will probe the technical details. Pick one project you can talk about inside out. 3. Coding exercise — your choice of take-home or live pair session. Take-home is async in your own IDE, any language, includes a README where you explain your decisions. Live pairing is 45 mins with a Monzo engineer, implementing functions against a provided interface — not leetcode, no binary trees, just practical work. Both end in a review call walking through your code. 4. Systems design (1 hour) — design a scalable system for a hypothetical problem using Excalidraw. They care about your reasoning, not your diagram. Don't namedrop buzzword tech unless you can defend why — they will push back. Know your CAP trade-offs and be able to explain your choices from first principles. 5. Behavioural (1 hour, two interviewers) — communication, how you deliver complex projects, how you work with a team. Be specific about what you did personally versus what the team did. STAR format, concrete examples.