Kevin Sheeran

blockchain, evm-based integration, software

• Design and develop smart contracts in Solidity (EVM) or Rust (Solana/Anchor) • Write unit, integration, and fuzz tests using Hardhat, Foundry, and Anchor • Build backend services for bot automation, relayers, and trading logic • Manage CI/CD pipelines for smart contract deployments and upgrades • Perform code reviews, gas profiling, and internal audits to ensure security • Monitor on-chain metrics and write Dune queries for real-time analytics

* Designed and implemented Solidity smart contracts for DePIN use cases (asset registration, incentive distribution, access control), supporting 10K+ on-chain entities with 99.9% execution success rate. * Built on-chain ↔ off-chain integration pipelines to synchronize physical infrastructure data with blockchain logic, processing 50K+ events/day with sub-second confirmation latency. * Optimized gas efficiency and transaction throughput across EVM-compatible networks, reducing average gas costs by ~25–35% and improving batch execution throughput by ~2×. * Developed and maintained Web3 APIs and contract interaction layers using ethers.js to support wallet operations and real-time data queries. * Applied modular contract architecture and upgrade patterns, enabling zero-downtime upgrades and reducing future feature rollout time by ~40%. * Implemented automated testing and validation workflows (Hardhat / Foundry), achieving 90%+ contract test coverage and eliminating critical issues before testnet/mainnet deployment. * Collaborated cross-functionally with product, backend, and frontend teams to deliver production-ready DePIN infrastructure components, accelerating release cycles by ~30% and improving cross-team delivery efficiency.

• Involved in interacting with public blockchains, such Tron, Bitcoin, Ethereum, implementing smart contracts, developing cryptocurrency wallets, and integrating payment gateways. • Collaborate with front-end developers and third-party cryptocurrency exchanges to integrate with their APIs and develop functionalities for buying, selling, and trading cryptocurrencies. Ensure secure and seamless integration between the backend system and the exchanges • Continuously optimize the performance and scalability of the wallet system to handle high volumes of cryptocurrency transactions efficiently. Analyze and fine-tune database queries, implement caching mechanisms, and identify and resolve performance bottlenecks • Implemented a blockchain-based automated payment routing solution which reduced the time taken to process payments by 55% and reduced manual errors in payment transaction processing. • Use Rust as backend language, familiar with actix-web framework.