Full Stack Engineer — Payments & ACH (AI-Native)

Why this role is different

Most full stack roles treat payments as a feature. Here it is the product. We run a high-volume ACH and reconciliation engine in one of the most compliance-sensitive corners of U.S. financial services — debits, credits, retries, virtual-account ledgering, and the messy reality of what happens when money does not move on the first try.

And we build it differently. We are AI-native by design — a small team shipping infrastructure-grade payments software at a velocity that should take 3× the headcount. Claude Code, Cursor, and agentic workflows are not perks here; they are how the work gets done. You will spend less time typing boilerplate and more time doing the thing that actually matters in payments: deciding what is correct, what is safe, and what happens when it fails.

We are past product-market fit: deep domain expertise, enterprise clients going live, and a founding team that has shipped payments infrastructure before.

We want engineers who pair real payments depth with real AI-tooling fluency — people who already know what NACHA return codes mean and know how to drive an agent through a reconciliation refactor without shipping a silent ledger bug.

How we work

• Agents are part of the team. You drive Claude Code / Cursor daily — scaffolding services, writing tests, refactoring, exploring unfamiliar code. You are judged on shipped, correct outcomes, not keystrokes.

• You write for agents, not just humans. Clear agents.md, tight specs, and well-scoped tasks are how you get leverage. Ambiguous instructions produce ambiguous code — in payments that is a defect.

• Evals and guardrails over vibes. AI-generated code moving money gets the same treatment as anything else: idempotency, audit logging, test coverage, and evals that catch regressions before prod does.

• Taste is the bottleneck. When the model can write the code, the differentiator is knowing what good looks like — schema design, failure modes, API contracts, observability. That judgment is the job.

What you will own

As a full stack engineer who lives on the backend, with an agent open in the next pane.

• ACH workflows end-to-end — origination, debits/credits, returns and retries, failure handling, virtual-account ledgering, and reconciliation

• Production backend services and REST APIs — versioned, contract-stable, hardened

• Event-driven architecture — AWS SQS, webhooks, retry and failure logic for reliable async processing

• PostgreSQL schemas that hold financial integrity under failure

• AI-assisted delivery — agents.md, eval sets, and tooling that make agentic development safe in a regulated domain

• CI/CD and test coverage that lets the team (and the agents) ship with confidence

• Internal React dashboards and ops tooling — often AI-scaffolded, always reviewed

• Design docs, run-books, and scalability notes — written because you are proud of the work

• Customer-facing work when it counts — supporting integrations, troubleshooting live workflows, representing the product outside the codebase

What we are looking for

Must have

Strong plus