Principal Software Engineer, AMER Payments

Trustly•San Francisco, CA

4d•$260,000 - $390,000•Hybrid

About The Position

Trustly is hiring a hands-on Principal Software Engineer to work on its US payments platform, which moves money between consumers, merchants, and banks. The role owns the code-level contracts connecting payments systems, bank connectivity, and risk decisioning, and builds difficult cross-system changes. Approximately two-thirds of the role is spent building. The engineer will lead the US Platform squad, set platform priorities and contracts across payments, bank connectivity, and infrastructure, and balance those priorities against business-squad needs, with program support from Core Payments TPMs. The role is hybrid and based in Trustly's San Francisco office, with team members expected in the office Tuesday through Thursday.

Requirements

Typically 15 or more years of software engineering experience, with principal-level scope across multiple teams and continued production coding.
Designed, built, and operated payment, banking, or ledger systems at scale.
Demonstrated ability to set technical direction through code and clear writing.
Product judgment to make platform trade-offs with business and product leaders as well as engineers.
Deep distributed systems expertise, including consistency, idempotency, concurrency, and failure handling.
Practical, current use of AI in engineering, with clear judgment about its limits in regulated systems.

Nice To Haves

Experience with ACH, RTP, FedNow, or open banking.
Experience unifying platforms across regions.

Responsibilities

Write and merge critical-path code every week, including reference implementations, contract tests, and difficult fixes.
Own versioned repository specifications for contracts between payments, bank connectivity, and risk, and maintain CI contract tests that fail the build when a contract breaks.
Build initial versions of difficult cross-domain changes and hand them to the owning team.
Own the global API specification in collaboration with engineers responsible for merchant-facing APIs.
Lead the technical response to cross-domain P0 or P1 incidents as part of the escalation rotation.
Run peak-event readiness, including load tests, failure drills, and capacity decisions.
Lead the US Platform squad by setting platform priorities and contracts across payments, bank connectivity, and infrastructure, balancing these against business-squad needs.