Brex · Primly Community

Did the full Brex onsite last month, here's what actually happened

backend_bekah · 5 replies

Just finished the Brex loop for a backend SWE role (mid-senior level). Wanted to write this while it's fresh because the advice I found online was pretty stale.

The rounds: Recruiter screen (30 min, standard, they asked about my fintech background specifically) Coding screen (60 min, HackerRank, one medium graph problem and one array manipulation, both felt doable but the bar was set by clean code + communication not just working code) Virtual onsite: 4 rounds in one day Another coding round, similar difficulty System design: design a payment processing system with at-least-once delivery guarantees. they REALLY care about idempotency here. i rambled about kafka for 10 minutes before they redirected me to ledger semantics. learn ledger design. Cross-functional behavioral (with a PM): stories about shipping under ambiguity, owning outcomes you didn't fully control Final behavioral with an eng manager: career trajectory, why Brex, a "tell me about a time you disagreed with a technical decision" type of thing

The behavioral rounds were substantial. Not afterthoughts. The PM-facing one especially felt evaluative on both sides. They wanted to know if I'd worked with product before or just handed off tickets.

I got an offer. Timeline was fast: recruiter screen to offer in 18 days. They said that's intentional.

5 replies

market_realist

the idempotency piece is real. got asked the same thing. they basically want you to explain why an API being called twice shouldn't double-charge a customer. if you've worked in fintech you know this cold. if you haven't, read up on idempotency keys before anything else.

backend_bekah

yes, and not just the theory. they asked what you do when the downstream system doesn't support idempotency natively. that's where it got interesting.

corp_refugee

18 days is legitimately fast for a startup-ish company. most of the Series B/C places I've interviewed take 6 weeks minimum because nobody owns the recruiting loop. sounds like Brex has it dialed in, at least for eng.

firsttime_mgr

curious about the cross-functional behavioral with the PM. was it conversational or did they ask formal STAR questions? trying to understand how prepared I should be vs. just being ready to tell stories naturally.

backend_bekah

conversational but structured underneath. they had a framework they were running even if it didn't feel like a quiz. i'd prep 3-4 concrete stories and let them steer, don't over-script it.