went through the brex frontend interview loop in march and want to leave a detailed breakdown since what i found online was pretty sparse.
recruitment moved fast. recruiter reached out on a monday, initial screen was thursday, and the full onsite was scheduled about two weeks later. four rounds total for my loop.
round 1: technical screen (60 min) basically a live coding session in coderpad. one question that started simple (flatten a nested array) and expanded into something more interesting: building a debounce function from scratch, then using it in a mini react component. interviewer was engaged, asked about edge cases. felt collaborative.
round 2: system design (frontend flavor) this is where brex differentiates from generic frontend loops. they asked me to design a real-time spend dashboard: components, state management approach, websocket vs polling tradeoffs, how you'd handle stale data. not a pure DSA round. they care about whether you think in terms of products, not algorithms.
round 3: product + behavioral what trade-offs have you made in a previous project that you'd make differently now. how do you push back on design when it's not feasible. had clear STAR-format stories ready and it went well. about 45 min.
round 4: bar raiser-style cross-functional senior engineer. asked about accessibility, performance profiling (core web vitals, layout shift), and what i'd do differently on a past project. a bit more philosophical.
total loop was about 4.5 hours across two days.
leveling note: i was interviewing for a mid-level role (they call it L3/L4 range). the bar felt real, not just "do you know react hooks". they genuinely care about product sense and frontend craft together, which i actually appreciate.
stack context: brex uses react, typescript, graphql. knowing graphql fragments helped me during the system design discussion.
overall positive experience. felt like interviewing with people who actually use the frontend.