Олексій

Demydov Oleksii
FULL STACK DEVELOPER
Telegram: @DemFam • WhatsApp: [open contact info](look above in the "contact info" section) • Available for remote / international opportunities
PROFILE
Full Stack Developer with professional freelance and project experience since 2021, building modern web applications from UI to backend APIs, databases and deployment. Strong focus on JavaScript/TypeScript, React and Node.js, with hands-on experience in REST APIs, Prisma ORM, MongoDB, MySQL, PostgreSQL, responsive interfaces, integrations and production deployments. Comfortable owning features end-to-end, from architecture and implementation to debugging and release.
TECHNICAL SKILLS
Frontend
JavaScript (ES6+), TypeScript, React.js, React Router, Redux, SCSS, CSS3, HTML5, MUI, Chakra UI, Radix UI, Framer Motion, Tiptap, ReactQuill
Backend
Node.js, Express.js, Prisma ORM, REST APIs, Python, FastAPI, Telegraf, authentication, validation, business logic
Databases
MongoDB, Mongoose, MySQL, PostgreSQL, Prisma ORM
Integrations
REST APIs, Telegram Web Apps, Telegram Bot API, EmailJS, Cloudinary, QR-code APIs, external service integrations
DevOps & Tools
Git, GitHub, Docker, Docker Compose, Nginx, PM2, Vercel, Netlify, GitHub Pages, Linux (Ubuntu/Debian), VS Code
Other
JSON, responsive design, API debugging, deployment, database-driven systems, performance and maintainability
PROFESSIONAL EXPERIENCE
Freelance / Contract Full Stack Developer | 2021 – Present
• Develop and maintain full-stack web applications for business and personal projects, working across frontend, backend, databases and deployment.
• Build responsive React interfaces and reusable UI components using modern JavaScript/TypeScript tooling and component libraries.
• Design and implement REST APIs with Node.js, Express.js and Prisma ORM, including validation, business logic, integrations and error handling.
• Work with MongoDB/Mongoose, MySQL and PostgreSQL for database-driven applications.
• Integrate external APIs and services, including Telegram Web Apps/Bot API, QR-code services, email integrations and media services.
• Deploy and maintain applications on Vercel, Netlify and Linux servers using Nginx/PM2 and Docker where appropriate.
• Investigate production issues, API errors and integration failures, improving reliability and maintainability of existing systems.
• Work directly with requirements, implementation, testing, debugging and delivery, taking ownership of features from idea to production.
SELECTED PROJECTS
Restaurant Menu & Ordering Platform
Full-stack web application for digital restaurant menus, administration and order-related workflows.
Stack: React.js, Node.js, Express.js, MongoDB, Mongoose, REST API, Bootstrap
E-commerce / Online Store Platform
Web stores with product management, shopping cart, order processing and backend API integration.
Stack: React.js, JavaScript, Node.js, Express.js, MySQL, REST API
QR Menu Generator
Application for creating and managing digital QR menus, with editable dishes, prices and images.
Stack: React.js, Node.js, Express.js, MongoDB, QR API
Telegram Web App / Game Backend
Interactive Telegram Web App with a Node.js backend, bot integration, statistics handling and persistent data.
Stack: React.js, Node.js, Express.js, Telegraf, MySQL, Telegram Web Apps, REST API
Business Websites & Landing Pages
Responsive websites and landing pages with modern UI, forms, integrations and deployment.
Stack: React.js, JavaScript, TypeScript, SCSS, MUI, Framer Motion, HTML5, CSS3
EDUCATION
T.H. Shevchenko National University Chernihiv Colehium (NUCHK) — Faculty of Physics and Mathematics, Mathematics and Informatics | Sep 2019 – Jun 2023
LANGUAGES
Ukrainian — Native • English — Pre-Intermediate