Senior Software Engineer, Ledger

Our client, early-stage Fintech company in San Francisco, are hiring a Senior Software Engineer to join the team remotely. The successful candidate will build and evolve the double-entry ledger that serves as the platform's financial system of record, while playing a key role in shaping the next generation of the platform, including a major ledger rebuild and the expansion of payment infrastructure.

Responsibilities

• Own and evolve the double-entry ledger, covering transactions, balances, holds, reversals, payment states, point-in-time balances and comprehensive audit trails.

• Design and build highly reliable money-movement infrastructure across ACH, instant payments, wires, cards and emerging settlement rails.

• Develop scalable payout and settlement systems, supporting instant payouts, batch processing and high-volume marketplace transactions.

• Build automated reconciliation systems that detect and resolve discrepancies across internal ledgers, banking partners and payment processors.

• Design and scale the infrastructure underpinning lending products, including disbursements, repayments, partial payments, reversals and complex loan lifecycles.

• Build resilient multi-provider payment architecture, incorporating webhooks, idempotency, retries, state machines and robust failure handling.

• Develop controls for high-value financial transactions, including fraud prevention, disputes, chargebacks, limits, holds and settlement management.

• Ensure complex financial activity is translated into a clear and intuitive customer experience, including balances, transaction histories, funding sources and settlement activity.

• Make pragmatic architectural decisions that balance delivery speed with financial accuracy, reliability, scalability and long-term maintainability.

• Provide senior technical leadership through architecture, code reviews, documentation and mentorship, raising engineering standards across the team.

Skillset

• Minimum of 5 years of professional software engineering experience, with a strong focus on backend, payments, fintech or financial systems.

• Strong proficiency in Python, PostgreSQL, AWS, SQL and relational data modelling.

• Hands-on experience building and operating real-world money movement systems, including ACH, instant payments, wires, cards or comparable payment rails.

• Experience designing, building, migrating or owning a double-entry ledger in a production environment.

• Strong understanding of webhooks, idempotency, race conditions, state machines, eventual consistency and reconciliation.

• Experience building highly reliable systems for high-value financial transactions, where accuracy, resilience and traceability are critical.

• Strong knowledge of transactional database architecture, particularly for high-volume, concurrent and financially sensitive workloads.

• Experience within payments, fintech, lending, marketplaces or other complex financial transaction environments.

• Strong ownership and product mindset, with the ability to balance speed, financial correctness, customer experience and long-term architecture.

• Experience with React and TypeScript would be a plus.

Benefits

• Salary: $140k - $180k DOE.

• Equity.

• Medical, dental, and vision coverage.

• 401(k).

• Remote working.