Principal Software Engineer, Fintech

Job Title:

Principal Software Engineer, Fintech

Team:

Engineering

Location:

Onsite - Sawtelle (Between Santa Monica & West LA) or San Francisco, CA

Employment Type:

Full-time, Salary, Exempt

Reports To:

Head of Engineering

About Plug

Plug is the marketplace for used electric vehicles. Consumers get an instant cash offer backed by battery-health data, and dealers across the US bid in real time on that inventory. Former Tesla executives founded Plug in 2023. We’ve facilitated $150M in EV sales and raised a $20M Series A led by Lightspeed Venture Partners.

Why Plug

You’ll own a piece of the biggest infrastructure opportunity in automotive.

You’ll work on a platform built exclusively for EVs, with nothing adapted from legacy automotive.

You’ll be part of an AI-native company. We’re rethinking how work gets done at a fundamental level.

You’ll work directly with operators who have scaled multi-billion dollar businesses in automotive, EV, and marketplaces.

You’ll have real ownership, high autonomy, and a direct line to company outcomes.

The Opportunity

Every transaction on Plug moves real money: consumer payouts, dealer settlements, lien payoffs, and auction proceeds. Today those flows run on infrastructure that was built to get us to $100M in volume, not to $1B. We need a technical architect to design the money systems that get us there: a ledger and payments architecture that’s correct, auditable, and fast, built to survive contact with banking partners, regulators, and scale.

We believe building consumer-facing product architecture and building money-facing architecture are fundamentally different disciplines, and rarely the same person’s strength. This role exists because we need someone whose primary craft is the latter: designing systems that hold up under regulatory scrutiny, banking-partner constraints, and financial audit, not just under user load.

What You’ll Do

• Own the architecture for Plug’s money-facing systems: ledger, payment disbursement, settlement, reconciliation, and lien and title payoff processing.
• Design a ledger that is deterministic, auditable, and gives a single, queryable source of truth for every dollar that moves through the platform.
• Architect systems that integrate directly with banking partners, payment processors, and lien and title servicers, working within the regulatory and compliance constraints those partnerships require, and doing so elegantly rather than with brittle workarounds.
• Make and document the core technical tradeoffs for financial systems: consistency vs. availability, idempotency, fault tolerance, and failure recovery for transaction-critical infrastructure.
• Partner with Product, Risk, Finance, and Compliance to translate business and regulatory requirements into system design.
• Set technical standards and review architecture for any system that touches money, acting as the final technical guardrail before it ships.
• Mentor and raise the technical bar for engineers working in and around the money systems domain, without owning formal people management.
• Evaluate and help decide when to build vs. integrate with external payments and banking infrastructure providers.

What You’ll Bring

• 10+ years in software engineering, with 5+ years working on B2B and B2C payments solutions.
• Direct experience designing and building payments, ledger, lending, or money movement infrastructure, not just consumer-facing payment systems.
• A genuine taste for elegance: the ability to design within real regulatory and stakeholder constraints in a way that stays efficient and clean, rather than accumulating one-off exceptions and technical debt to satisfy each new requirement.
• Proven experience designing systems within regulatory and banking-partner constraints. You understand what it takes to build infrastructure that a bank, processor, or regulator will actually sign off on.
• Deep expertise in distributed systems: 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. You’ll be the first and primary technical owner of this domain.
• Strong cross-functional collaboration skills. You can translate complex technical tradeoffs for Product, Risk, Finance, and Compliance stakeholders.
• International or cross-border money movement experience is a plus, but not required.
• Experience with title, lien, lending, or marketplace escrow-like flows is a plus.
• You work agent-first. You are comfortable orchestrating multiple coding agents, defining clear acceptance criteria, and reviewing AI-generated output to a high bar, and you have a point of view on where that is and is not appropriate in code that moves money.