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🌟 Your Trusted Partner for Web & Web3 Development 🌟 Hi, I’m Viktor, the founder of Vizzwo, a Ukraine-based company specializing in creating modern Web and Web3 solutions. We provide end-to-end product development, covering every stage: ✅ Design creation ✅ Development ✅ Deployment on AWS or/and launching on the blockchain mainnet 💻 Our Technology Stack: 🚀 Frontend Development: - Vanilla JavaScript - ReactJS - Next.js - TypeScript 🔧 Backend Development: - Golang - PostgreSQL / Redis / MongoDB - Solidity ☁️ Infrastructure & DevOps: - AWS - Docker, Kubernetes - Terraform ❓ Didn’t find the technology you’re looking for? No worries! Just send me a message—we likely have the expertise you need. ✨ Let’s bring your ideas to life. Whether it’s a modern website, a high-performance application, or an innovative Web3 solution, Vizzwo is here to help. 📩 Message me today, and let’s get started!

👨‍💻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.

🔝 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.

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.

Summary: A highly motivated Blockchain Engineer with a robust blend of theoretical knowledge and hands-on development expertise. With a proven track record in mastering and implementing cutting-edge technologies, I pride myself on ensuring client satisfaction and fostering long-term relationships. My experience spans across various blockchain platforms and back-end technologies, making me a versatile asset in the ever-evolving tech landscape. Education: KHARKIV POLYTECHNICAL INSTITUTE Master’s degree in Software Engineering SEP 2009 - JUN 2014 Doctor of Philosophy - PhD, Computer ScienceDoctor of Philosophy - PhD, Computer Science SEP 2019 - MAR 2024 Languages: Ukrainian: Native Speaker Russian: Native Speaker English: Upper-Intermediate Technical Proficiency: Blockchain Technologies: Ethereum, Solana, Solidity, Rust, Hadhat, NodeJS, Web3JS, VueJS, and more. Back-end Technologies: Firebase, Kafka, Go base, Confluent-kafka, Akka, Cassandra, and more. Database Management: PostgreSQL, MongoDB, MySQL, Redis. Tools & Platforms: Vs Code, IntelliJ IDEA, WebStorm, Atom, Jenkins, Docker, Git, SVN, Jira, Trello. Projects: ChromaWay: Blockchain technology company focused on relational blockchain architecture. Roci.fi: A DeFi primitive for permissionless under-collateralized lending on Ethereum. Highvibe Network: Blockchain-based ecosystem for immersive experiences and multidimensional learning. BigTaurus: Crypto and Forex training platform with Token BGT CLUB. Korporatio: Merging International Business Company (IBC) and Decentralized Autonomous Organisation (DAO) to form Smart Companies.

VADYM MYKHAILENKO Smart Contract & BackEnd Engineer EXPERIENCE 2024 - 2026 Shogun (Intensity Labs) Lead Backend & Smart Contract Engineer * Designed and built core protocol architecture for an intents-based trading system across EVM, Solana, and Sui: * Developed secure and cost-efficient smart contracts for intent creation, validation and execution * Led backend development for the protocol’s execution infrastructure, including: o Designed orders processing, verification pipelines, auctions, external API for order access and integrations o Implementing on chain efficient trade estimations and safe executions * Architected protocol to support: o Flexible order configuration: single chain / cross chain, market / limit / DCA orders, with new parameters (like trailing stop loss) addable with minimal changes to core logic o 200+ concurrent trades (orders executions) o A scalable multi-chain design extendable to any number of EVM chains * Built cross-chain trading aggregation API (TypeScript) with smart contracts (Solidity/Yul) for extended functionality which: * Supported 13+ chains across 3 chain types * Estimated, compared and provided best quotes for single chain and cross chain trades * Built a high-performance Rust indexer for trading and launchpad protocols across EVM and Solana, covering 30+ protocol types Tech stack: Rust, Solidity, Yul, Anchor, MOVE, TypeScript, PostgreSQL, WebSocket, alloy, Docker 2022 - 2024 BabyDoge Senior smart contracts developer * Developed and deployed smart contracts o DEX, Farming, NFT, Presale and more * Built supporting indexers for smart contract data and protocol operations * Worked on partner integrations, issue analysis, and user-facing protocol incident investigation * Contributed to products that reached: * $75M+ peak TVL * $1B+ trading volume * No hacks/exploits Tech stack: Solidity, Yul, TypeScript, Hardhat, ethers.js 2021 - 2022 ThreeEquals Smart contracts developer * Developed and deployed numerous smart contracts across different use cases * Wrote technical and business documentation for protocol and product requirements Tech stack: Solidity, TypeScript, Hardhat, ethers.js EDUCATION Master's degree 2011 National Aviation University Information protection of computer systems and networks PROFESSIONAL SUMMARY Senior protocol engineer with experience building smart contracts and backend systems for trading, execution, and cross-chain infrastructure. Worked across EVM, Solana, and Sui, with hands-on ownership of execution-critical systems including order processing, trading, estimations, and indexers. Strong focus on performance, security, flexibility, and building reliable systems that operate under real production load. Languages: * English * Ukrainian * Russian