Senior Java Engineer
You design, develop, and optimize payment backend systems, including scan-to-pay functionality, transaction processing, fund flows, crypto and stablecoin payments, and payment-status synchronization. You troubleshoot production issues and improve architecture, monitoring, reliability, and observability.
Responsibilities
- Design, develop, and optimize OKX Pay payment backend systems
- Build QR and scan-to-pay capabilities
- Implement transaction processing, clearing, settlement, reconciliation, refunds, and callback notifications
- Build crypto and stablecoin payment capabilities
- Integrate on-chain asset movement with traditional payment experiences
- Diagnose and resolve complex production issues
- Improve architecture, code quality, monitoring, alerting, compensation, and observability
Requirements
- Solid Java development skills
- Spring Boot and mainstream Java backend frameworks
- Experience building high-concurrency, high-availability systems
- Payment system experience covering orders, state machines, callbacks, reconciliation, refunds, clearing, settlement, and exception compensation
- Scan-to-pay, acquiring, aggregated payment, merchant payment, or wallet payment experience
- Architecture design skills
- Understanding of idempotency, retries, compensation, deduplication, concurrency protection, and fund security
- Understanding of crypto and stablecoin payments and on-chain asset movement
- Production troubleshooting, log analysis, tracing, performance optimization, and recovery skills
- Experience with stablecoin payments, account and ledger systems, blockchain fundamentals, risk control, or high-concurrency transaction systems
Benefits
- Comprehensive insurance coverage for employees and their dependants