Senior Backend Engineer

Senior Backend Engineer About us We're creating the foundational backend systems that power private market access, from secure authentication and transaction processing to portfolio management and regulatory compliance. The Role We're looking for a Senior Backend Engineer to own the systems where money moves and balances have to be correct — the ledger, transaction processing, and the settlement and reconciliation workflows behind our platform.

This is the correctness core of what we build. If a balance is wrong, a transaction double-processes, or a reconciliation silently drifts, nothing else we build matters. You'll design the double-entry ledger, the money-movement engine, and the long-running state machines that carry complex financial workflows to completion reliably over hours, days, or weeks.

You'll reason about idempotency, concurrency, partial failure, and replay as a matter of habit, not as an afterthought. You'll own core infrastructure decisions and set the standard for how we build financial systems.

What You'll Do

• Design and build the double-entry ledger and money-movement engine that all transactions reconcile against
• Model complex financial workflows as robust, observable state machines that run reliably over long periods
• Guarantee financial correctness under concurrency: idempotent operations, transactional integrity, and reconciliation that ties out to the cent
• Handle partial-failure and replay cases so no event is lost, duplicated, or applied twice
• Build secure, well-versioned APIs
• Design and optimize PostgreSQL schemas and data models
• Debug production issues and own the reliability of mission-critical financial workflows What We're Looking For
• 5+ years of backend development on production systems
• Demonstrated money-movement correctness experience: you've built a ledger, settlement system, payments core, or transaction-processing system and can talk in detail about how you kept it correct
• Concurrency and idempotency depth: you can explain, from experience, how you handled double-processing, race conditions on balances, and replay
• Reconciliation experience: you've built or owned systems that had to tie out exactly, and you know what happens when they don't
• Strong TDD practices: you write tests first and maintain comprehensive coverage
• Domain-Driven Design expertise: you model complex financial domains accurately
• Deep PostgreSQL knowledge: schema design, transactions, isolation levels, optimization
• Strong in a modern backend stack: we work in TypeScript/Node.js, Go and on the JVM ecosystem; we value real depth in either and the range to pick up the other
• Cloud deployment experience
• Startup mentality: comfortable with ambiguity, high autonomy, driving solutions without detailed specs Nice to Have
• Payments, banking, brokerage, or investment-platform systems experience
• Securities, custody, or portfolio/NAV domain knowledge
• Event-driven architectures and message queues
• Infrastructure as Code (Terraform, Cloud. Formation)
• Understanding of KYC/AML or compliance frameworks
• Accounting principles or financial modeling