Hire the Best Smart Contracts Developers
in Ukraine

👨‍💻4yrs+ Experience A smart contract developer with over 4 years of experience building DeFi and blockchain infrastructure on EVM networks. I specialize in smart contract architecture, protocol integration, and security-focused development. I have experience working with Uniswap V3/V4, account abstraction, staking protocols, and upgradeable contract patterns. I am passionate about building scalable decentralized financial infrastructure.

Do you want to turn your ideas into reality? I'm an experienced full-stack web developer with a proven track record of successfully delivering projects for companies of all sizes. From user-friendly interface design to robust enterprise solutions, I can do everything to make your project stand out from the crowd. What I can offer: - Full-stack expertise: I am proficient in all major web development technologies and can quickly adapt to new tools or frameworks as needed. - Back-End development: I create secure, scalable, and efficient server systems according to your needs. - Blockchain and cryptocurrency: Experience in creating smart contracts, integrating blockchain solutions, and developing decentralised applications, better known as dApps. - SEO and performance optimisation: Your website should not only look amazing, but also perform fantastically and rank high in search results. - Perfect project management: I'll see your project through from idea to final rollout with the utmost precision and care. Why work with me? - I am passionate about creating scalable, customised solutions to meet your business goals. I'm fluent in a variety of technologies and pride myself on finding the right tools to get the job done efficiently. Regular communication and collaboration are at the heart of my process; I'm here to ensure your vision is realised every step of the way. Let's work together to create something amazing. Message me today, and let's discuss how I can help turn your vision into reality!

I work as a Full Stack Developer, Web3 Developer and Blockchain Developer building production-ready applications that connect business logic with blockchain infrastructure. As a Web3 Developer, I focus on wallet integrations, smart contract interactions, and scalable dApp architecture. As a Blockchain Developer, I design and implement secure, efficient systems on top of modern blockchain networks. As a Full Stack Developer, I ensure everything works end-to-end, from frontend to backend, clean, scalable, and maintainable. As a Web3 Developer, Blockchain Developer, and Full Stack Developer, I’ve worked on real-world products involving NFT platforms, DeFi systems, and exchange-related applications. My main specialization as a Web3 Developer and blockchain developer is building integrations between applications and blockchain networks, including wallet connections, contract execution, and real-time data handling. I work deeply with blockchain infrastructure, ensuring applications behave reliably under real user conditions. The projects I’ve worked on include: - NFT platforms as an experienced nft developer: landing-based apps, SPA and multi-page applications, NFT marketplaces, hybrid exchange systems, and Uniswap forks - Smart contract integrations as a Blockchain Developer: contract interaction using web3 and ethers libraries, handling transactions, events, and contract state as a smart contract engineer - Wallet integrations as a Web3 Developer: Metamask connections, custom Web3 context implementations, and secure interaction flows - Backend systems as a Full Stack Developer: building services with Node.js and TypeScript, working with MongoDB (Mongoose), PostgreSQL (Supabase), and Prisma for NFT data and application logic - Blockchain data querying as a Blockchain Developer: using Apollo Client with Uniswap subgraphs to fetch and process on-chain data efficiently - Gas optimization as a Web3 Developer: creating services that fetch gas price predictions and apply them to outgoing transactions - Exchange integrations as a Full Stack Developer: working with Binance API, order creation, and financial workflows As a Web3 Developer and Blockchain Developer, I have strong experience working with solidity, including creating ERC20 mintable tokens and handling contract deployment pipelines with Hardhat. As a Blockchain Developer, I have also handled migration of NFT systems from Ethereum to non-Ethereum environments, adapting logic, contracts, and integrations accordingly. As a Web3 Developer, I ensure compatibility across different chains and environments. On the frontend, as a react developer and web developer, I build modern, responsive interfaces using React, Next.js, and TypeScript. I’ve worked with Material UI, styled-components, Bootstrap, SCSS, and CSS modules, ensuring clean UI systems and maintainable code. On the backend, as a Full Stack Developer, I design APIs, manage data flows, and ensure consistency across distributed systems. I’ve also worked with state management (Redux, Redux Toolkit, redux-localstorage-simple), data layers (Prisma, MongoDB, PostgreSQL), and tooling (ESLint, Prettier), ensuring code quality and long-term maintainability across projects. As a Web3 Developer, Blockchain Developer, and Full Stack Developer, I focus on performance, reliability, and scalability. Many blockchain products fail not because of the idea, but because of weak implementation. As a Web3 Developer, I make sure integrations with wallets and smart contract systems are stable and predictable under real usage. As a Blockchain Developer, I focus on transaction correctness, contract behavior, and data consistency. As a Full Stack Developer, I ensure the entire system behaves correctly across frontend, backend, and infrastructure. In addition, as a Web3 Developer, I work on improving UX around blockchain interactions, reducing friction for users interacting with nft platforms and contract-based systems. As a Blockchain Developer, I focus on writing efficient and maintainable solidity code. As a Full Stack Developer, I connect all layers into usable, scalable products. Beyond blockchain, my broader experience as a web developer, wordpress developer, and mobile app developer allows me to approach projects from a full product perspective, ensuring usability, performance, and scalability in real-world conditions. I continuously improve as a Web3 Developer, Blockchain Developer, and Full Stack Developer, staying up to date with modern tools, frameworks, and best practices across blockchain and web development. If you’re looking for a Web3 Developer, Blockchain Developer, or Full Stack Developer to build NFT platforms, smart contract systems, or scalable applications connected to blockchain, I can help deliver a reliable, production-ready solution.

Is your blockchain product ready for real users, or is it a prototype that breaks under live transactions? Most Web3 projects fail at the boundaries between smart contracts, wallets, trading operations, and backend systems. 🏆 20+ years architecting production systems at principal engineer level 📊 $200K+ earned on Upwork across 32 architecture projects 🎯 100% Job Success Score, Top Rated Plus on Upwork ⚡ 11 years architecting Fintech / Trading / Accounting solutions ⚡ 8 years architecting blockchain products across Bitcoin, EVM, Solana ecosystems 💼 CEO at Osambit, a 20-person engineering team ✅ Enterprise Blockchain Architect certified, former Sr Principal Engineer at Nordstrom ⭐⭐⭐⭐⭐ "We've had the opportunity to collaborate with the Osambit team, and it's been a great experience. They're highly professional, responsive, and truly understand the final goal. Their technical expertise and ability to deliver on time have been key to the success." (Alwyn V., IXO World) As a Blockchain Architect with 20+ years of production engineering experience and two years focused on Web3, I design blockchain and fintech products that operate reliably beyond a demo. I work across Solana and EVM networks—including Ethereum, Polygon, Base, BSC, and Arbitrum—as well as enterprise platforms such as Hyperledger Fabric and Besu. My work connects secure smart-contract, wallet, payment, and remittance flows with the backend systems, operational controls, and user experiences a real product needs. Every engagement starts with architecture: chain selection, custody and transaction boundaries, compliance-aware workflows, failure modes, scalability, and security. That architecture-first approach helps blockchain and neobanking products withstand live usage, not just testnet scenarios. 🔶 Centralized exchange: architecture for trading operations, wallet flows, and reliable backend integration 🔶 Custodial wallets: secure custody, transaction handling, and multi-wallet platform architecture 🔶 Trading automation system: real-time blockchain-integrated trading workflows with operational safeguards 🔶 Liquidity automation system: DeFi and liquidity-management automation across Solana and EVM ecosystems 🔶 Fintech, neobanking & remittance apps: payment, account, wallet, and cross-border transfer architecture 🔶 Bitcoin mining facility control panel: operational dashboard and control-system architecture for mining infrastructure 🔶 Blockchain-integrated game: NFT features, token and wallet integrations, and production-ready game backend design 🔶 Enterprise blockchain solutions: permissioned-network architecture and public-chain integrations using Hyperledger Fabric or Besu 🔶 Nordstrom (Sr Principal Engineer, 5 years): architected 9+ enterprise systems | led 10 offshore engineering teams | supply chain, payment, logistics domains WHAT I DO ✅ Blockchain Architecture: chain selection, system design, security boundaries, and production rollout planning ✅ Solana Development: Rust programs, SPL standards, RPC integrations, and high-throughput DeFi systems ✅ EVM & Smart Contracts: Solidity development and integrations for Ethereum, Polygon, Base, BSC, and Arbitrum ✅ Wallet & Custody Systems: custodial wallet architecture, secure transaction handling, and multi-wallet integrations ✅ Fintech, Neobanking & Remittance: payment flows, account and wallet systems, cross-border transfers, and operational controls ✅ DeFi, Trading & Liquidity Automation: trading workflows, liquidity systems, DEX integrations, and operational controls ✅ NFT & Tokenized Products: NFT minting, metadata, marketplace and royalty logic, and blockchain-integrated game features ✅ Enterprise Blockchain: Hyperledger Fabric and Besu solutions, permissioned-network architecture, and API or oracle integrations ✅ Full-Stack Web3 Platforms: React interfaces, Node.js or Python backends, web3 integrations, and real-time transaction services ✅ Production Infrastructure: AWS, Docker, Kubernetes, CI/CD, observability, automated testing, and scalable data systems WHO I WORK WITH 🎯 B2B and B2C companies building blockchain products, fintech and neobanking apps, exchanges, wallets, DeFi platforms, or games 🎯 Founders and CTOs who need Web3, payment, or remittance systems running in production with real users and real assets 🎯 Teams with multi-week engagements (4+ weeks minimum), not 5-minute tasks 🎯 Companies that understand blockchain architecture is a system design and security problem, not just a smart-contract problem 🎯 Clients who value senior engineering judgment over the cheapest hourly rate MY PROCESS 1️⃣ Architecture Review: 24-hour turnaround on an initial system map, risk review, and scope estimate for your blockchain or fintech product. Close collaboration with business and deep domain immersion. 2️⃣ Design: chain selection, smart-contract, wallet, payment, and remittance boundaries, backend integration, and security plan 3️⃣ Build: production blockchain or fintech

We are a Blockchain & Web3 development team delivering full-cycle solutions - from idea to mainnet launch Our core focus is building scalable, secure, and production-ready Web3 products using modern tech stack and proven architecture. 🔧 Our Tech Stack Blockchain: Solidity, EVM (Ethereum, Arbitrum, BNB Chain, Polygon, Avalanche), Smart Contracts, Web3 integrations Frontend: React.js, Next.js, Web3.js, Ethers.js, Wagmi, WalletConnect Backend: Node.js, Express.js, NestJS, REST APIs, WebSockets Mobile: React Native (Web3 wallets, mobile dApps) Infrastructure: Docker, AWS, CI/CD, Hardhat, Foundry 💼 What We Build Smart Contracts (ERC20, ERC721, ERC1155) Token Development & TGE Launch DeFi Platforms (staking, lending, yield farming) DApps (full-stack Web3 applications) Launchpads & IDO Platforms Crypto Payment Integrations (on/off-ramp, wallets) Custom Web3 Dashboards & Admin Panels (реально відображає ваші кейси типу токенів, TGE, launchpad ) ⚙️ How We Work End-to-end development (Smart Contracts + Frontend + Backend) Clean, maintainable and scalable architecture Security-first approach (testing, audits, best practices) Fast delivery with clear milestones 🧠 Why Clients Choose Us Strong expertise in Web3 / Blockchain / DeFi Experience with tokens, staking, launchpads, and complex dApps Deep understanding of product + business logic, not just code Dedicated team (Blockchain + Frontend + Backend + PM) 📩 Let’s Build Your Web3 Product If you are looking to build a token, DeFi platform, dApp or full Web3 ecosystem - we can help you deliver it fast and right.

🔝 TOP 10% of Upwork Agencies 💯 Job Success ⭐️ 5-Star Rating 🏆 Hackathon winners 🔟/🔟 Smart Contracts Rating Audited by Hacken ✅ ⭐️⭐️⭐️⭐️⭐️ "We look forward to continuing our collaboration on the next phase! Yevhen, Dexola, and the rest of the team have been an absolute pleasure to work with. Very knowledgeable and responsive, would highly recommend!" ⭐️⭐️⭐️⭐️⭐️ "It was a pleasure working with Yevhen. He is highly skilled and very professional. Will definitely work with him again. Highly recommended." As a CTO with over 10 years of experience and 45 blockchain-based projects completed, I have a proven track record in delivering high-quality, scalable, and secure web solutions. My expertise lies in blockchain and Web3 technologies. I am passionate about building innovative blockchain and Web3 products that solve real-world problems. Furthermore, I am committed to working closely with my clients to understand their needs and ensure that their projects are a success. 📍 Blockchain & Web3 Development: - DAO, DeFi and GameFi solutions - EVM Chain (Ethereum/ETH) - Solana - Solidity, Rust 📍 Smart Contracts: - NFT Smart Contract - Staking, Minting, Airdrops - Security Smart Contracts Audit 📍 Full-Stack Development - Node.js, React.js, web3.js, Vue.js, TypeScript etc. - API Integration - Building & Deploying Scalable and Secure Applications 📍 Trading & Automation: - Decentralized Exchange (DEX/CEX) - Trading Bots (bonding curve keys, volume bot, telegram bot) - Crypto Casinos 📍 Integration & Bridges: - Wallet Integration (WalletConnect, Coinbase Wallet, etc.) - Blockchain Bridges ⌛️ Proven success in delivering projects on time and within budget 🙌 Excellent communication and interpersonal skills Let's hop on a call and discuss how I can make your project happen.