Solid Java backend fundamentals. ~5–10 years of Java backend experience with a strong grasp of collections, concurrency, thread pools, the JVM, network communication, and common performance issues. Proficient with Spring Boot, Spring Cloud, MyBatis, or comparable stacks, able to independently design and build medium-to-large backend modules and reason about the mechanics behind the frameworks you use
Strong system design ability. Experience with complex or high-concurrency systems; comfortable with idempotency, retries, compensation, caching, message queues, distributed locks, data consistency, rate limiting, and service degradation. Able to own module- or service-level design and clearly explain the core flow, failure scenarios, and key trade-offs
Cognitive ability and judgment. Able 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 — rather than reflexively adding complexity
Drive and ownership. Able to independently own a module or project end to end, from design through development, testing, and launch. Proactively communicates and resolves dependencies, risks, and blockers, and follows through on launch outcomes rather than stopping at code merge
Blockchain or wallet experience. Experience with wallets, blockchain, trading platforms, on-chain data services, or related systems. Understands addresses, public/private keys, mnemonics, transaction signing, broadcasting, on-chain confirmation, gas, and nonce; familiar with the transaction mechanics of at least one of EVM, Tron, or Solana, and with token standards such as ERC-20 and TRC-20. (Strong backend fundamentals and fast learning can offset gaps in blockchain coverage.)
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. Actively considers malformed input, duplicate requests, privilege bypass, and data-leak risks when building transaction features
Independent production troubleshooting. Able to diagnose live issues via log analysis, metrics monitoring, distributed tracing, and thread/memory analysis; can form hypotheses and narrow scope even with incomplete information. Hands-on experience with performance degradation, timeouts, message backlogs, data inconsistencies, memory issues, or unstable third-party services
Engineering in the AI era. Willing to use AI coding tools to improve daily efficiency and able to judge whether AI output meets real business requirements before shipping it. Has a basic understanding of prompts, context management, RAG, AI agents, and MCP, or a genuine willingness to keep learning — treating AI as an engineering tool, not requiring an algorithm/model-training background
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 — e.g. AI code review, development agents, MCP servers, intelligent troubleshooting, or knowledge bases
Follows developments in AI coding assistants and LLM applications and shares practical takeaways with the team