Oleksandr

Blockchain Developer ( Smart Contracts, Solidity, Rust, Token Launch )

Self-Employed • Autônomo

Jun 2023 - Present • 2 yrs 11 mos

I develop Solana and Ethereum smart contracts, DeFi protocols, NFT platforms, and full-stack Web3 applications for startups and crypto teams. I specialize in secure, scalable, and production-ready blockchain systems. Key Skills / Achievements • Developed Ethereum smart contracts (ERC20, ERC721, ERC1155) for DeFi and NFT projects • Built Solana programs using Rust and Anchor with high-performance on-chain execution • Created staking and liquidity systems for DeFi protocols • Integrated Web3 frontends (React / Next.js) with blockchain backends • Developed crypto trading bots, Telegram bots, and automated arbitrage systems • Built blockchain analytics platforms and on-chain data pipelines • Optimized smart contracts for performance, security, and scalability Tech Stack / Tools Solana • Ethereum • Rust • Solidity • Anchor • Hardhat • Web3.js • Node.js • React • TypeScript • PostgreSQL • MongoDB • APIs • Docker

Senior Blockchain Developer | OKX Finance August 2021 - July 2023

OKX Finance • Freelance

Aug 2021 - Jul 2023 • 1 yr 11 mos

Designed end-to-end Web3 and blockchain applications, combining frontend, backend, and blockchain integration. Key Skills / Achievements • Built full-stack applications using React, Next.js, Node.js, and TypeScript • Developed REST & GraphQL APIs and backend systems for blockchain and enterprise apps • Integrated wallets (MetaMask, Phantom, WalletConnect) for Web3 platforms • Created real-time dashboards and trading interfaces for crypto platforms • Managed database architecture (PostgreSQL / MongoDB) and data pipelines Tech Stack / Tools React • Next.js • Node.js • TypeScript • JavaScript • Web3.js • Ethereum • Solana • Rust • PostgreSQL • MongoDB • APIs • Docker

Blockchain Developer

Hacken • Freelance

Apr 2019 - Jul 2021 • 2 yrs 3 mos

Developed smart contracts, DeFi protocols, and Web3 infrastructure for blockchain-based applications. Key Responsibilities • Built Ethereum smart contracts (ERC20 / ERC721 / ERC1155) • Developed DeFi protocol features including staking and liquidity systems • Designed secure smart contract architecture • Integrated Web3 frontends with blockchain backends • Built blockchain data services and APIs • Optimized smart contract performance and security Tech Stack Ethereum • Solidity • Hardhat • Web3.js • Node.js • React • PostgreSQL