Backend Engineer - Crypto and Payments
Core
Build the financial core of a stablecoin and digital-assets wallet, specifically the ledger, posting, reconciliation, and financial-control capabilities.
Role type
Senior Core Backend Engineer (Financial Systems)
Builds
Event-sourced, append-only double-entry ledger, posting engine, settlement platform, and reconciliation controls for a global stablecoin product.
Domain
Fintech, Digital Banking, Crypto Payments, Financial Core
Deliverable
production ML models | product features
Required skills
Double-entry ledger modeling, Payment posting engine design, Relational database (PostgreSQL/MySQL), Idempotency and exactly-once-effect patterns, Event-driven architecture, Financial reconciliation, Java or Python, Transaction isolation and concurrency control
Preferred skills
Stablecoin and digital asset experience, Fireblocks or TigerBeetle integration, Card issuing and processing, AWS serverless (Lambda, EventBridge, SQS), General ledger integration
Technologies
PostgreSQL, MySQL, Java, Python, AWS (Lambda, EventBridge, SQS, Step Functions), Kafka, Fireblocks, TigerBeetle
Responsibilities
Build and improve an event-sourced, append-only double-entry ledger and its account, journal, posting, balance, hold, fee, FX, and adjustment models; Implement posting rules and invariants to keep journals balanced and prevent unauthorized value creation; Build transaction-processing flows for authorisation, holds, capture, settlement, reversals, refunds, chargebacks, and corrections; Apply idempotency, deduplication, sequencing, and concurrency controls to payment, card, custody, and blockchain events; Build reconciliation controls across managed CASP ledger, Fireblocks, on-chain data, fiat ramps, card processing, treasury, and accounting systems; Contribute to event schemas, financial data contracts, versioning, replay, and backfill approaches; Work with finance and treasury to create accounting evidence, GL exports, reserve and liquidity views; Own monitoring and production support for components, including incident response and root-cause analysis
Seniority
Senior, hands-on IC
