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

Why Plug

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

The Opportunity
Every transaction on Plug moves real money: consumer payouts, dealer settlements, lien payoffs, and auction proceeds. Today, those flows run on infrastructure built to get us to $100M in volume, not $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.

Compensation and Benefits
Annual salary: $222,256 to $259,324

Benefits & Perks

• Health, Vision, and Dental insurance

• 401(k) plan

• Equity

• Unlimited PTO

• Dog-friendly office and on-site EV charging

• 30-day remote work from anywhere policy

• Ongoing opportunities for growth and development

This full-time role is in-person, ideally based in Sawtelle (between Santa Monica and West Los Angeles), and we will also consider San Francisco-area candidates. We will not provide relocation assistance to successful candidates. We do not offer sponsorship at this time.