Brex
Brex Software Engineer Interview
Focus areas and question themes aggregated from 2 current openings — pick any opening below and practice a voice mock calibrated to it.
Brex Software Engineer mock interview
A live voice mock calibrated to this role — real questions, the real follow-up rhythm, and a score at the end. Free to start.
Software Engineer postings in this family both carry the same 'Backend' title but diverge in practice: one is deep in Brex's credit-decisioning and risk infrastructure, the other builds customer-facing spend-management features end-to-end from Vancouver. Both test ownership in a fintech environment where reliability and correctness carry real financial weight.
What this interview tests
- Backend systems fundamentals — The Credit Limit posting tests backend development in Kotlin and Micronaut alongside real-time financial data pipelines and event-driven credit-decisioning architecture.
- Full-stack feature ownership — The Vancouver posting tests owning a feature end-to-end, from data model through client-side code to shipped metrics.
- ML-in-production constraints — The Credit Limit posting tests integrating a risk model into a live underwriting flow without breaking latency or SLA requirements.
- External and bank connectivity — The Credit Limit posting names integrations with bank-connectivity providers like Plaid, Finicity, and Teller directly.
- Cross-functional collaboration — The Vancouver posting tests close collaboration with Sales and Support to shape banking-experience features; the Credit Limit posting instead tests operating in a regulated fintech domain.
- Reliability and operational ownership — The Credit Limit posting tests testing and reliability practices for systems managing large financial exposure and on-call observability; the Vancouver posting tests architecting and testing client-side code for reliability.
Common question themes
Design a real-time pipeline for processing financial transactions with sub-second decisioning latency.
This is the lead question theme for the Credit Limit Engineering posting.
Walk through a feature you owned end-to-end, from data model to shipped UI.
This is the lead question theme for the Vancouver posting.
How would you integrate a risk model into a live underwriting flow without breaking SLAs?
This exact scenario is named in the Credit Limit posting's question themes.
Describe a time customer or support feedback changed your technical design.
Close collaboration with Sales and Support on feature design is named directly in the Vancouver posting.
Walk through a time you owned a problem end-to-end, from API design to data model to production observability.
End-to-end ownership including observability is named as a focus area for the Credit Limit posting.
How do you architect and test client-side code so it's reliable?
Client-side architecture and testing is named directly as a focus area for the Vancouver posting.
Tell me about your experience with Kafka or event streaming and the trade-offs involved.
Kafka and event-streaming trade-offs are named explicitly in the Credit Limit posting's question themes.
Tell me about a time you had to polish a feature beyond just making it work.
This is listed directly among the Vancouver posting's question themes.
Likely format
Neither posting specifies an interview format, so this is inferred from question style. The "design" and "walk through" phrasing on both postings points to a system-design or coding round scoped to the specific team's domain, either credit-decisioning pipelines or full-stack feature architecture, plus a behavioral round on operating in a regulated or customer-facing fintech context. Expect a stronger latency and reliability angle on the Credit Limit posting and a stronger UI-polish and customer-feedback angle on the Vancouver posting.
All 2 Brex openings in this role
Frequently asked questions
Is 'Software Engineer II, Backend' actually a backend-only role?
Not necessarily. The Vancouver posting under this same title is explicitly full-stack, including client-side code and testing, while the Credit Limit posting is backend-focused with real ML-serving and event-streaming depth.
Do I need fintech or credit-risk domain experience going in?
It's not required upfront, but the Credit Limit posting explicitly asks about experience in a regulated or fintech domain and what changes about how you build there, so be ready to discuss it even without direct credit-risk background.
Is this role remote or in-office?
The Vancouver posting is explicitly hybrid, three days a week in the office; the Credit Limit posting doesn't specify a location arrangement.