Senior Software Engineer, Affirm Bank

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most.

About the Role

Affirm is building its own bank — and this role sits in the engineering team that runs it. We're looking for a Senior Software Engineer to join a deliberately small, AI-native team that owns the systems behind Affirm's bank: vendor-integrated banking infrastructure, durable workflows, data platform, and the operational tooling that holds it all together. You'll work alongside other senior engineers, with direct exposure to senior bank and Affirm leadership, to launch the bank's deposit product, drive loan originations through the bank entity, and bring card issuing online in time.

This is a rare opportunity to shape a new business from its very first systems — a startup-like build inside an established company. You'll be one of the first engineers on Affirm's bank, moving with the speed, autonomy, and ownership of an early-stage team while leveraging Affirm's brand, distribution, and consumer reach. The team is small and AI-native, the surface area is broad, and the work meaningfully matters — every system you ship serves real customers under a real bank charter. The systems you build and the standards you set will directly determine what the bank becomes.

What You'll Do

Own bank systems end-to-end. Design, build, integrate, operate, and own incident response for the bank's core technical surfaces: cloud infrastructure, data platform, durable workflow orchestration, core banking configuration, CI/CD, networking, and the Bank ↔ Affirm Inc integration. Generalist breadth is expected.

Be a force multiplier on a small team. Set and improve code review and design standards, lift the bar on examiner-readable documentation, and make the team you join more effective than the team you found. Every Senior IC on this team has outsized influence on what gets built and how.

Ship AI-first. Lean on AI tools and agentic workflows as a multiplier for code, design review, runbook generation, and operations. Push yourself and your teammates on what an AI-leveraged team can deliver.

Own vendor relationships. Carry one or more of the bank's third-party vendor relationships end-to-end — integration, operations, escalation, and audit. The bank's tech stack is intentionally vendor-leveraged, and ownership of those relationships is an engineering responsibility.

Build for examiners. Partner with Legal, Compliance, Risk, and Internal Audit to factor in compliance from day one. Write decisions, designs, and runbooks to a standard that holds up under examiner and audit review.

Own the operational posture of your work. Set up monitoring, alerting, runbooks, and the practices that keep the bank's systems reliable, observable, and audit-ready. The bank operates with a small operational footprint by design — help keep it that way. You will support the operations and availability of your team’s artifacts by creating and monitoring metrics, escalating when needed, and supporting “keep the lights on” & on-call efforts.

Influence beyond the team. Communicate technical strategy, tradeoffs, and constraints clearly to non-engineering stakeholders (bank executives, Compliance, Risk), and engineers outside the bank. The bank doesn't operate in isolation, and the relationships you build with non-bank engineers shape how cleanly the integration boundary works.

Help grow talent as the team grows. As new engineers join over time, they'll join an engineering function whose practices and standards you helped establish. Provide feedback, mentor peers, and lead by example.

What We Look For

6+ years of software engineering experience, with senior-strong, hands-on builder credentials and a track record of taking ownership end-to-end through launch and operations

Comfortable in ambiguity — you move fast, ask hard questions, and take ownership before being asked, while balancing speed with engineering judgment

Bias toward simplicity — experience operating in or building toward a small, lean engineering culture where the engineering bar is high and the surface area is kept intentionally tight

Hungry to leverage AI to drive outcomes — fluent with AI-assisted development tools (Claude, Cursor, Codex, agentic workflows) and actively pushing yourself and your team to use them as a multiplier for code quality, velocity, and what a deliberately small team can ship

Strong systems thinking across public cloud infrastructure (AWS preferred), infrastructure-as-code (Terraform), and cloud data platforms (Snowflake or comparable)

Regulated-environment experience — direct work in banking, payments, securities, healthcare, or another setting subject to external examination, where the work involves examiner-facing documentation and decisions

Comfortable as the technical face of your work to non-engineering stakeholders — Compliance, Risk, Finance, outside counsel, and examiners — and able to document decisions so they hold up under audit review

Exceptional written and verbal communication — you can distill complex technical, regulatory, and operational concepts into clear narratives for executives and non-engineering audiences

This position requires either equivalent practical experience or a Bachelor’s degree in a related field

Nice to have