Staff/Senior Java Engineer, OKX Web3 Wallet

As a Staff/Senior Java Engineer at OKX, you own core modules of OKX Wallet, a self-custody wallet that operates in a multi-chain, multi-asset, high-concurrency environment shaped by on-chain state uncertainty and strict fund-security requirements. You combine the complex-systems challenges of traditional internet backends with the transaction, signing, and on-chain interaction problems unique to blockchain, working independently on core modules while exercising sound judgment on complex problems and coordinating across teams.

What you'll do

• Own core wallet backend modules: build and continuously improve address management, asset synchronization, transaction construction, broadcasting, on-chain confirmation, gas estimation, nonce management, and transaction-state tracking, keeping stability, performance, and maintainability front of mind.
• Build transaction and on-chain interaction scenarios including transfers, token approvals, contract interactions, cross-chain swaps, DApp connections, and signature-request handling; understand a transaction's full lifecycle and diagnose issues like stuck transactions, duplicate submissions, state inconsistencies, and on-chain success not reflected in the business system.
• Support multi-chain and new-chain integration across EVM, Tron, and Solana, contributing to technical research, integration design, and feature development while accounting for differences in address models, account systems, transaction structures, signing methods, fees, confirmation mechanisms, node stability, asset sync, exception compensation, monitoring, and security boundaries.
• Ensure stable operation through monitoring, alerting, rate limiting, graceful degradation, retries, compensation, data reconciliation, and troubleshooting; when incidents occur, investigate root causes and drive systemic fixes.
• Drive your projects to delivery by taking ownership of the modules and projects you're responsible for, proactively syncing information, surfacing dependencies and risks, and driving issues to resolution across product, QA, frontend, infrastructure, and other backend teams.
• Continuously raise engineering quality by participating in design discussions, code reviews, and system optimization, spotting unreasonable designs, duplicated logic, and latent risks, and proposing actionable improvements.
• Apply AI in daily development by using AI coding tools such as Claude Code, Cursor, and Codex to assist with code comprehension, scaffolding, unit tests, code review, troubleshooting, refactoring, and documentation, validating AI output for correctness, project conventions, performance, and security.

What you bring

• Approximately 5–10 years of Java backend experience with a strong grasp of collections, concurrency, thread pools, the JVM, network communication, and common performance issues; proficiency with Spring Boot, Spring Cloud, MyBatis, or comparable stacks.
• Strong system design ability with experience in complex or high-concurrency systems; comfort with idempotency, retries, compensation, caching, message queues, distributed locks, data consistency, rate limiting, and service degradation.
• Cognitive ability and judgment to understand context and goals on ambiguous problems, separate symptom from root cause, and choose a fitting solution based on business value, user experience, stability, cost, and security.
• Drive and ownership: ability to independently own a module or project end to end from design through development, testing, and launch, proactively communicating and resolving dependencies, risks, and blockers.
• Blockchain or wallet experience including understanding of addresses, public/private keys, mnemonics, transaction signing, broadcasting, on-chain confirmation, gas, and nonce; familiarity with the transaction mechanics of at least one of EVM, Tron, or Solana, and with token standards such as ERC-20 and TRC-20.
• High security awareness sensitive to private-key, signing, permission, and user-asset security, familiar with replay protection, API authentication, tamper resistance, sensitive-data protection, and least-privilege principles.
• Independent production troubleshooting ability to diagnose live issues via log analysis, metrics monitoring, distributed tracing, and thread/memory analysis, with hands-on experience addressing performance degradation, timeouts, message backlogs, data inconsistencies, memory issues, or unstable third-party services.
• Willingness to use AI coding tools to improve daily efficiency and ability to judge whether AI output meets real business requirements before shipping it, with basic understanding of prompts, context management, RAG, AI agents, and MCP.

Nice to have

• Integration work on new public chains, new asset standards, or cross-chain protocols
• Familiarity with WalletConnect, DApp Browser, or signature-request handling
• Knowledge of MPC, multisig, hardware wallets, or TEE-based key-security schemes
• Experience with Swap, staking, cross-chain bridges, or DeFi aggregation
• Address risk detection, allow/deny lists, anti-fraud, or wallet risk-control experience
• High-concurrency transaction systems, blockchain node services, on-chain data indexing, or transaction-state-tracking systems
• Familiarity with RPC calls, block scanning, chain reorgs, transaction compensation, and reconciliation mechanisms
• JVM performance tuning, stability governance, or complex production-incident experience
• Cross-team collaboration with a track record of driving projects to delivery
• Real projects built with AI such as AI code review, development agents, MCP servers, intelligent troubleshooting, or knowledge bases
• Regular engagement with developments in AI coding assistants and LLM applications, sharing practical takeaways with the team

What we offer

• Competitive total compensation
• Comprehensive insurance coverage for you and your dependents

About OKX

OKX Wallet is OKX's self-custody wallet built for users worldwide to securely and conveniently store, manage, and use their on-chain assets across multiple blockchains and asset types.