Software Engineer

The role

You will own financial partner integrations from API design to production hardening. You will build automation for trading and treasury operations and design systems for fiat and crypto rails.

What you will do

• Own integrations with banks, payment providers, and liquidity venues end-to-end
• Build integrations robust to vendor reality and schema changes
• Build messaging and notification systems with signature verification and replay protection
• Maintain and evolve the reconciliation layer across all connected payment rails
• Identify and replace manual workflows in onboarding, compliance, and back-office operations with automation
• Enable self-service for internal ops teams and customers
• Design and build the automation layer for trading and treasury operations
• Set and maintain engineering standards for payment integrations
• Mentor engineers on money movement systems
• Ship and critically review AI-assisted code

Required qualifications

• 6 to 10+ years of backend engineering experience in cross-border payments, stablecoins, FX infrastructure, or crypto custody
• Production experience with crypto rails including Ethereum, Tron, Solana, bridging stablecoins, and DeFi protocols
• Production experience with fiat rails such as SWIFT, SEPA, FPS or CHATS
• Production experience with durable workflow orchestration
• Strong TypeScript/Node and Postgres in a money context
• Hands-on third-party API integration experience

Nice to have

• Senior profiles are also considered favourably
• Temporal strongly preferred

About the company

Codex is building the infrastructure for stablecoin-based cross-border payments. It is a small team backed by Circle, Coinbase, Dragonfly, Wintermute, and Cumberland.