Staff Software Engineer, Payment Gateway

Trustly•San Francisco, CA

3d•Hybrid

About The Position

At Trustly, we're building a smarter, faster, and more secure financial future by revolutionizing the world of payments. As a global leader in Open Banking Payments, we are establishing Pay by Bank as the new standard at checkout, providing unparalleled freedom, speed, and ease to millions of consumers and merchants worldwide. Trustly moves money between consumers, merchants and banks across the US. We are building our US engineering hubs in San Francisco and New York, starting with a small group of staff engineers who will take technical ownership of our most critical systems. You will own Payment Gateway end to end: its architecture, its reliability, its operation in production, and where it goes next. You'll own the systems that move money through bank rails once a payment is authorized: rail selection and submission over ACH and RTP, per-bank file formats, our banking partner integrations, and the returns and reversals that come back from the banks. You'll start by learning a mature, business-critical codebase fast, using AI tools to map it and writing the documentation others will build from. Within your first year, you'll help hire and lead the team that owns it with you.

Requirements

Typically 10+ years building and operating production software systems, including several years owning systems at staff level or equivalent.
Hands-on experience with payments, banking or other financial systems where correctness, auditability and uptime matter most.
You have carried the pager for systems you built, and improved them because of it.
A track record of taking over an unfamiliar, business-critical codebase and becoming its owner.
Daily use of AI coding tools (such as Claude Code, Cursor or Copilot), with clear views on where they help and where human review has to hold.
Strong distributed systems design: data consistency, idempotency, concurrency.
Clear writing. Your design docs and incident write-ups are the ones other people reuse.
Production experience with Java or a comparable backend language.
Experience building money movement systems on ACH, RTP or similar payment rails, working directly with banking partners.

Nice To Haves

Experience with ACH, RTP, FedNow or open banking.
Experience helping build a new engineering hub or leading a major platform transition.

Responsibilities

Own the architecture, service contracts and production health of Payment Gateway.
Own the operation of your services: on-call, SLAs, incident response and root-cause fixes. There is no separate operations team; the team that builds the service runs it.
Meet the observability standards set for every service, and make the service measurably better each quarter.
Use AI tools to understand existing code quickly, then turn what you learn into design docs, interface definitions and runbooks that engineers and AI agents can work from.
Partner with the engineers who run these systems today, across the Americas and Europe, to transfer knowledge.
Direct AI-assisted implementation: write and close implementation plans, review output against requirements, and own integration testing.
Help hire and shape the team that will own this domain.