Staff Software Engineer, Payment Gateway

Trustly • San Francisco, CA

4d • Hybrid

About The Position

Trustly is hiring a Staff Software Engineer to take end-to-end technical ownership of its Payment Gateway, a business-critical system that moves money between consumers, merchants, and banks across the United States. The role owns the gateway’s architecture, service contracts, production reliability, operations, and future direction. Its domain includes selecting and submitting payments over ACH and RTP, supporting bank-specific file formats and banking partner integrations, and handling returns and reversals from banks.

The engineer will quickly learn and document a mature codebase, using AI tools to help map existing systems and produce design documentation, interface definitions, and runbooks. They will direct AI-assisted implementation, verify work against requirements, and own integration testing. The role works with engineers across the Americas and Europe to transfer system knowledge, and will help hire and lead the team that will own the domain.

This is a hybrid role based out of Trustly’s San Francisco office, with an in-office expectation Tuesday through Thursday.

Requirements

• Typically 10 or more 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 are important.
• Experience carrying the on-call pager for systems you built and improving those systems based on operational experience.
• 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, and sound judgment about their use and the need for human review.
• Strong distributed-systems design skills, including data consistency, idempotency, and concurrency.
• Clear writing skills, including producing reusable design documents and incident write-ups.
• Production experience with Java or a comparable backend language.
• Experience building money-movement systems on ACH, RTP, or similar payment rails and 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.
• Operate the services, including on-call duties, SLAs, incident response, and root-cause fixes; the team that builds the service also runs it.
• Meet observability standards and measurably improve the service each quarter.
• Use AI tools to understand the existing codebase and document findings in design documents, interface definitions, and runbooks for engineers and AI agents.
• Partner with engineers across the Americas and Europe to transfer knowledge about the systems.
• Direct AI-assisted implementation by writing and completing implementation plans, reviewing output against requirements, and owning integration testing.
• Help hire and shape the team responsible for the Payment Gateway domain.

Benefits

• Flexible paid time off and generous PTO accrual plans.
• Comprehensive medical, dental, vision, and other insurance.
• Flexible spending and health savings account plans for medical and dependent care.
• Home office setup allowance.
• Internet stipend.
• Retirement plan match for 401(k) and RRSP.
• Gender-neutral paid parental leave.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed