Staff Engineer, API & Partner Integrations

Trustly•San Francisco, CA

23h•Hybrid

About The Position

Trustly is hiring a Staff Engineer to take end-to-end technical ownership of API and Partner Integrations, a critical domain that moves money between consumers, merchants, and banks across the US. The role owns the architecture, reliability, production operation, and future direction of API connectivity, including direct bank APIs (FDX), core and online banking provider APIs, and third-party aggregators. This includes partner consent, tokens, certification, and readiness for open banking rules such as Section 1033. The engineer will quickly learn and document a mature, business-critical codebase, working with engineers across the Americas and Europe to transfer knowledge. The role carries operational responsibility for the services, including on-call, SLAs, incident response, and root-cause fixes; there is no separate operations team. The engineer will use AI tools to understand and implement changes, direct AI-assisted development, and review and test its output. Within the first year, the engineer will help hire and lead the team that will own this domain. This is a hybrid role based out of Trustly's San Francisco office, with team members expected in the office Tuesday through Thursday. Applications are accepted on an ongoing basis.

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 pager for systems you built and improving those systems as a result.
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 judgment about their strengths and the need for human review.
Strong distributed systems design skills, including data consistency, idempotency, and concurrency.
Clear writing skills, including design documents and incident write-ups that others can reuse.
Production experience with Java or a comparable backend language.
Experience building integrations with bank APIs, core banking or online banking providers, or data aggregators, including consent and token management.

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 API and Partner Integrations.
Operate the services, including on-call coverage, SLAs, incident response, and root-cause fixes.
Meet service observability standards and measurably improve the service each quarter.
Use AI tools to understand the existing codebase and produce 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 closing implementation plans, reviewing output against requirements, and owning integration testing.
Help hire and shape the team that will own the domain.