OKX - Senior / Staff Engineer, DEX Trading System

• Design and develop backend services for quote aggregation, order management, transaction orchestration, and execution tracking. • Build reliable integrations with DEX protocols, liquidity sources, blockchain RPC providers, and indexing services. Define clear order and transaction state models, with robust handling of retries, duplicate requests, partial failures, and recovery. • Ensure trading services remain reliable under high concurrency, traffic spikes, and degraded external dependencies. • Implement appropriate rate limiting, concurrency controls, resource isolation, and graceful degradation. • Optimize database access, transaction boundaries, caching, and asynchronous processing. Establish monitoring, alerting, load testing, and incident-response practices for critical trading flows. • Support trading workflows across multiple blockchain ecosystems. Handle transaction submission, confirmation tracking, failed or dropped transactions, and chain reorganizations. • Build data synchronization and reconciliation mechanisms to maintain consistency between backend records and on-chain execution. • Translate product requirements into practical technical designs and production-ready services. • Own features through implementation, testing, rollout, and post-launch operation. • What We Look For In You • 5+ years of professional backend engineering experience, including ownership of production systems. • Strong proficiency in Java and its backend ecosystem. Solid understanding of concurrency, distributed systems, relational databases, caching, and messaging systems. • Experience building high-availability services and diagnosing performance or reliability issues in production. • Understanding of blockchain transactions, smart contract interactions, and common DeFi trading mechanisms. • Ability to independently drive a feature from technical design through production deployment. Strong ownership, sound engineering judgment, and effective cross-functional communication.