intellltech

Sr. Blockchain & Full Stack Dev

Experienced Blockchain Engineer with 10+ years of expertise in developing decentralized applications (dApps), smart contracts, and blockchain integrations. Skilled in Ethereum, Solidity, Solana, Hyperledger, and Layer-2 scaling solutions, with a strong background in DeFi, tokenomics, and cross-chain interoperability. Proven ability to build secure and gas-optimized smart contracts, conduct security audits, and implement cryptographic techniques for enhanced blockchain scalability and reliability. Proficient in full-stack development, integrating React.js, Node.js, Web3.js, and cloud infrastructure (AWS, GCP) to develop robust and scalable Web3 applications.


Experience: 10 years

Yearly salary: $100,000

Hourly rate: $55

Nationality: 🇯🇵 Japan

Residency: 🇺🇸 United States


Experience

Senior Blockchain Developer
DXDao
2023 - 2025
Led the design, development, and auditing of smart contracts across Ethereum and Layer-2 solutions (e.g.,Optimism, Arbitrum), with a strong focus on scalability, security, and the integration of decentralized governance mechanisms for DXdao’s ecosystem. Developed custom blockchain connectors to integrate DXdao's decentralized applications (e.g., Omen, Mesa, CowSwap) with leading DeFi protocols such as Uniswap, Aave, and MakerDAO, enabling seamless interaction and driving user adoption within the decentralized finance space. Mentored junior and mid-level blockchain developers, conducting detailed code reviews, championing best practices, and hosting internal workshops on the latest blockchain innovations, security patterns, and governance models. Enhanced DXdao's platform performance by optimizing smart contract gas usage, streamlining data fetching methods, and introducing off-chain indexing to improve scalability and reduce operational costs. Contributed to the expansion of DXdao’s cross-chain capabilities, enabling the use of its products across multiple blockchains, including Ethereum and other Layer-2 solutions, to broaden the reach and adoption of DXdao’s ecosystem. Conducted rigorous internal smart contract audits, collaborating with external auditors to ensure the security of new contract deployments. Led the implementation of comprehensive testing protocols using tools like Hardhat, Truffle, and Foundry. Stayed at the forefront of the latest trends in DeFi, Layer-2 scaling solutions, and decentralized governance models. Evaluated emerging technologies and protocols for potential integration into DXdao's ecosystem, ensuring the DAO’s continuous innovation. Worked closely with cross-functional teams, including product managers and UX/UI designers, to align backend architecture with user-facing features, optimizing both performance and usability.
Blockchain Developer
TokenMind
2022 - 2023
Developed and deployed Solana smart contracts using Rust and Anchor, optimizing for performance, security, and gas efficiency. Designed and implemented Solana Program Library (SPL) token contracts, NFT minting programs, and DeFi protocols. Built full-stack dApps integrating Solana-based smart contracts with React/Next.js frontends, ensuring a seamless user experience. Led smart contract audits and optimizations for both Solana (Rust) and Ethereum-based (Solidity) contracts, improving security and efficiency. Designed and deployed EVM-compatible smart contracts using Solidity, Hardhat, and Foundry, including ERC-20, ERC-721, and ERC-1155 standards. Integrated Solana and EVM-based contracts into cross-chain interoperability solutions, enhancing liquidity and user engagement across multiple ecosystems. Contributed to IDO platforms, NFT marketplaces, and DeFi applications by developing secure, scalable smart contracts and backend APIs. Worked closely with UI/UX teams to deliver decentralized applications (dApps) with optimized performance on both Solana and Ethereum L2s (Optimism, Arbitrum, Polygon).
Blockchain Developer
ShareRing
2019 - 2022
Architected and developed a custom blockchain solution based on the Cosmos SDK/Tendermint, enabling a robust platform for decentralized asset sharing and information exchange across multiple industries, including travel, logistics, and mobility. Designed and implemented a secure Decentralized Identity (DID) system, providing users with self-sovereign control over their identity data. Integrated ShareRing blockchain solutions into the travel and logistics industries, enabling seamless cross-border asset sharing, reducing transactional friction, and enhancing access to global shared mobility service. Developed and deployed ShareRing tokens on EVM-compatible blockchains, creating a decentralized, secure ecosystem for asset exchange. Built and managed smart contracts for DeFi applications, including cross-chain swapping, bridging, and liquidity management, improving the platform’s scalability and interoperability. Collaborated closely with project stakeholders to define project requirements, design blockchain solutions, and oversee the full development lifecycle from initial concept through deployment and testing, ensuring that all deliverables met business and technical objectives. Leveraged AWS cloud infrastructure and Docker containerization to ensure the platform's scalability, security, and high availability, improving performance and reducing latency for asset-sharing services. Led the end-to-end development process, overseeing the design, coding, testing, and deployment phases to ensure the successful delivery of blockchain solutions aligned with ShareRing's business goals.
FullStack Developer
BitQuick
2013 - 2018
Designed and built a custom cryptocurrency exchange platform, implementing secure, scalable architecture for seamless trading of multiple digital assets. Developed the frontend with React.js, Redux, and Next.js, ensuring a responsive, high-performance UI for a smooth trading experience. Built the backend using Node.js, Express.js, and PostgreSQL, optimizing API performance and enabling secure trade execution. Integrated blockchain technology into the full-stack web application, utilizing Web3.js, Ethers.js, and smart contract interactions to facilitate on-chain transactions. Deployed and managed cloud infrastructure on AWS (EC2, S3, Lambda, RDS), implementing auto-scaling and load balancing for reliability. Developed real-time order matching algorithms and WebSocket-based market data feeds to provide instant trade updates. Worked directly with product and business teams to define and enhance the user experience (UX/UI), ensuring blockchain functionalities were intuitive for non-technical users. Implemented authentication and security best practices using JWT, OAuth, and multi-signature wallet integration to safeguard user accounts and assets. Led CI/CD automation efforts using Docker, Kubernetes, and GitHub Actions, improving deployment efficiency and reducing downtime. Monitored and optimized platform performance, reducing API response times by 30% and improving database query efficiency.

Skills

aws
cosmos
docker
ethereum
ethereumjs
git
golang
hardhat
hyperledger-fabric
javascript
jira
kubernetes
mongo
nextjs
node
postgres
python
react
rust
solana
solidity
tailwind
truffle
web3js
english