Principal Software Engineer, Fintech

Plug Technologies•Los Angeles, CA

11h•Onsite

About The Position

Plug is hiring a Principal Software Engineer to own the architecture of its money-facing systems, including ledger, payment disbursement, settlement, reconciliation, and lien and title payoff processing. The role will design financial infrastructure that is correct, auditable, and fast enough to support the company’s growth, banking partnerships, regulatory obligations, and financial audits. A central goal is a deterministic ledger that provides a single, queryable source of truth for every dollar moving through the platform. The engineer will design systems integrating with banking partners, payment processors, and lien and title servicers, and document core technical tradeoffs involving consistency, availability, idempotency, fault tolerance, and failure recovery. They will partner with Product, Risk, Finance, and Compliance to turn business and regulatory needs into system designs, set standards and review architecture for systems that touch money, mentor engineers without formal people-management responsibility, and help evaluate whether to build or integrate external infrastructure. This is a high-autonomy role in a fast-moving startup, serving as the first and primary technical owner of the money systems domain. The position is full-time and in-person, ideally in Sawtelle between Santa Monica and West Los Angeles; San Francisco-area candidates will also be considered. Plug does not provide relocation assistance or sponsorship at this time.

Requirements

10+ years of software engineering experience.
5+ years working on B2B and B2C payments solutions.
Direct experience designing and building payments, ledger, lending, or money movement infrastructure, rather than only consumer-facing payment systems.
Proven experience designing systems within regulatory and banking-partner constraints.
Deep expertise in distributed systems, including transaction integrity, financial data consistency, idempotency, auditability, and fault tolerance at scale.
A track record of owning architecture decisions end to end, from design through implementation and long-term maintainability.
Comfort operating with high agency in an ambiguous, fast-moving startup environment and serving as the first and primary technical owner of a domain.
Strong cross-functional collaboration skills and the ability to explain complex technical tradeoffs to Product, Risk, Finance, and Compliance stakeholders.
Comfort orchestrating multiple coding agents, defining clear acceptance criteria, reviewing AI-generated output to a high bar, and judging when agent use is appropriate for code that moves money.

Nice To Haves

International or cross-border money movement experience.
Experience with title, lien, lending, or marketplace escrow-like flows.

Responsibilities

Own the architecture for Plug’s ledger, payment disbursement, settlement, reconciliation, and lien and title payoff systems.
Design a deterministic, auditable ledger that provides a single, queryable source of truth for every dollar moving through the platform.
Architect integrations with banking partners, payment processors, and lien and title servicers while accommodating their regulatory and compliance constraints.
Make and document technical tradeoffs for financial systems, including consistency versus availability, idempotency, fault tolerance, and failure recovery.
Partner with Product, Risk, Finance, and Compliance to translate business and regulatory requirements into system design.
Set technical standards and review architecture for systems that touch money, serving as the final technical guardrail before launch.
Mentor engineers working in and around the money systems domain without taking on formal people management.
Evaluate and help decide when to build versus integrate with external payments and banking infrastructure providers.