Senior Backend Engineer – Fiat & Stablecoin Infrastructure

## About OneDosh OneDosh is a global fintech building fast, transparent, and affordable cross-border payments between the U.S. and Africa—starting with the U.S.–Nigeria corridor. We combine regulated fiat infrastructure with modern stablecoin rails to deliver instant payouts, better FX, and a radically improved experience for diasporians sending money home and Nigerians sending money abroad. We are building real financial infrastructure — not a demo app. Reliability, compliance, and precision matter. ## Role Overview We are hiring a Senior Backend Engineer with deep experience in fiat money movement and stablecoin infrastructure to help design, build, and scale our core payments systems. You will work on the systems that move real money across: - ACH / wires - Local payout rails (e.g., NIP / NUBAN) - Card networks - Stablecoin networks (e.g., USDC, ERC-20, Base, etc.) This role requires strong backend engineering fundamentals combined with practical payments and financial systems experience. ## Responsibilities ### Core Payments Infrastructure - Design and build reliable systems for fiat on-ramps and off-ramps - Integrate with banking partners, payment processors, and card issuers - Implement ledger-based transaction tracking and reconciliation systems - Ensure atomicity and correctness in money movement flows ### Stablecoin & Blockchain Integration - Integrate with stablecoin rails (e.g., USDC, ERC-20, Base, etc.) - Build secure wallet management and transaction broadcasting systems - Monitor confirmations, handle re-orgs, and manage gas optimization - Implement safeguards around private key custody and signing flows ### Ledger & Accounting Integrity - Design double-entry ledger systems - Maintain pipelines between: - Internal ledger - Bank statements - Card processors - On-chain transactions - Ensure idempotency and fault tolerance in transaction processing ### Reliability & Risk Controls - Implement transaction monitoring hooks and compliance triggers - Build rate limits, freeze logic, and exception-handling workflows - Design for 99.99%+ uptime and high transaction success rates ### AI Agents - Building AI agents for workflow resolutions - Solving novel use cases in development with AI enabled workflows - Experience in top model agent APIs ### Security & Compliance - Work closely with compliance to ensure flows meet AML/KYC requirements - Protect PII and financial data using industry best practices - Implement encryption, secure key storage, and audit trails ## Required Experience - Building 0 to 1 - 5+ years experience - Direct experience integrating global fiat payment rails - Hands-on experience working with stablecoins or blockchain integrations - Experience building or maintaining financial ledger systems - Understanding of transaction states (pending, settled, reversed, failed) - Familiarity with idempotent APIs and distributed systems - Experience at a fintech, neobank, remittance, or crypto company - Knowledge of FX pricing and spread logic ## Nice to Have - Experie