Build messaging / notification systems with signature verification and replay protection; pin schemas against real sandbox behaviour; design for failure at every layer
Maintain and evolve the reconciliation layer across all connected payment rails — fees, settlement windows, and exception handling as first-class concerns
Operational Automation
Identify manual workflows in onboarding, compliance, and back-office operations and systematically replace them with product and automation
Enable self-service for internal ops teams and customers, reducing engineering dependency for routine operational tasks
Work closely with Compliance and Operations to understand where the friction is and build the tooling that removes it
Treasury & Liquidity Automation
Design and build the automation layer for Codex's trading and treasury operations — automated position management, liquidity routing, and risk controls
Design for failure: clear handling of automated decision failures, position unwinding, and safe degradation
Engineering Standards
Set and maintain the engineering standard for how payment integrations are built at Codex — idempotency, audit trails, fail-closed design, exact decimal arithmetic, and deterministic durable orchestration
Mentor engineers on the hard parts of money movement systems
Continuously design and build for security, hardening our systems
Ship and critically review AI-assisted code with the judgement to identify plausible but incorrect output or output detrimental to a product’s long-term health and sustainability
What We're Looking For
6 to 10+ years of backend engineering experience in cross-border payments, stablecoins, FX infrastructure, or crypto custody (Senior profiles are also considered favourably)
Production experience with both crypto rails (on-chain settlement on major networks like Ethereum, Tron and Solana; bridging major stablecoins; DeFi protocols) and fiat rails (SWIFT, SEPA, local schemes such as FPS or CHATS)
Must-have: Production experience with durable workflow orchestration — Temporal strongly preferred. Includes deterministic replay, safe versioning of live workflows, idempotency keys, and compensation logic
Must-have: Strong TypeScript/Node and Postgres in a money context — fail-closed design, exact decimal arithmetic, append-only audit trails
Must-have: Hands-on third-party API integration experience, including vendors with incomplete documentation, webhook reliability requirements, and schema instability
