Principal Payments Engineer

Payabli•Miami, FL

About The Position

This is the founding hire for the Payments Core team, responsible for centralizing critical money movement functions like rails, batching, funding, reconciliation, and ledgering. The role involves owning the reliability and correctness of these systems at scale, ensuring payments infrastructure is robust and trustworthy. The Principal Payments Engineer will be the most senior individual contributor on the team, reporting to the CTO on an interim basis, and will set the technical foundation for future hires and existing engineers in this domain. The position requires an entrepreneurial mindset, comfort with ambiguity, and the ability to make decisions with incomplete information, taking ownership of outcomes.

Requirements

12+ years building production payments or financial systems.
Direct experience operating at $10s to $100s of billions in GMV.
Track record of owning architecture and seeing big decisions through to production.
Direct experience designing or operating a double-entry ledger in production.
Direct experience building idempotent, exactly-once payment flows in real-time, high-throughput systems.
Experience designing distributed data architecture and petabyte-scale storage systems.
Experience building high-throughput services that hold sub-50ms latency under real production load.
Deep experience with settlement and reconciliation against real external data (bank files, card network settlement, ACH returns).
Experience with multi-rail money movement (ACH, wire, RTP/FedNow, card networks) and multi-FI orchestration.
High technical bar set through influence and example.

Nice To Haves

Prior experience at a payments platform operating at comparable scale (e.g., Stripe, Block/Square, Modern Treasury, Marqeta, Adyen).
Experience modernizing or hardening a payments platform at scale without stopping money movement.
Familiarity with PCI DSS, ISO 20022 messaging, and scheme-level settlement file formats.

Responsibilities

Guarantee correctness at scale, ensuring payments execute exactly once even under failure conditions.
Define and implement a first-class, testable property for payment execution correctness.
Set the API contract for internal and external use, including versioning, backward compatibility, and webhook delivery guarantees.
Direct money-movement architecture, including multi-rail orchestration (ACH, wire, RTP/FedNow, card networks) and routing strategies.
Own batching, funding, and reconciliation processes, ensuring accuracy against settlement data and fast exception handling.
Build reliability and observability from day one, establishing architecture review, RFC standards, and monitoring/alerting.
Set the bar for the team by establishing practices, review standards, and technical hiring criteria for future payments engineers.