Kostiantyn A.

Full-Stack JavaScript Developer | React/Next/Node/Express

Hi everyone 👋 I'm a high-skilled (7+ years) Full-Stack Developer. I have 8,000+ hours of a proven track record and 16 completed jobs here on Upwork. Through many projects, I have mastered problem-solving skills and just fell in love with what I'm doing. Creating new products is what brings me much more joy than anything else. I especially like small and big projects that require uncommon approaches and use of the most efficient methods. My skills: — JavaScript/ES6; — Typescript; — Cursor, Claude Code; — Node.js, Express.js; — React.js/Next.js; — Redux/Redux Toolkit/Tanstack-Query/Zustand/React Context; — HTML5, CSS3 and LESS (SASS); — React-Native IOS/Android, Expo; — Material UI, Ant Design, styled-components, Tailwind; — Agile: Jira, Trello, Notion, Linear and Slack; Other: Webpack, REST APIs, Git, Docker, GitHub Actions (CI/CD pipeline). Databases: MongoDB, Mongoose, Firebase/Firestore, Planescale, Supabase, ClickHouse Familiar with: AWS, Electron, Inngest, Redis. I'm open to both part-time and full-time positions, so feel free to send me an invitation any time! You'll be rewarded once we work together :)