Fedir Kopakov
Senior Frontend & Full-Stack JavaScript Engineer
12 Years of Experience
Summary
Top expert with 12 years of experience as a developer, fractional CTO, product designer, and UX/UI specialist.Super detail-oriented, results-driven, and always meet deadlines. I also focus on the highest quality.
Hard worker with strong personal qualities.
~200 completed projects and a Top 0.5% Upwork ranking, I’ve earned a reputation for delivering consistent results - on time and with excellence.
Experience
Senior Full-Stack & Frontend & UI Developer
Freelance - Upwork, Elance, oDesk, and others
Sep 2013 - May 2025
Worldwide · Full-time · Remote
Worked as a full-time independent developer for ~200 projects, consistently ranked in the Top 0.5% of freelancers on Upwork. Delivered scalable, production-grade applications for startups, SMBs, and enterprises across various industries.
- Led end-to-end product development, from architecture to deployment.
- Designed and built SaaS platforms, MVPs, and interactive dashboards.
- Maintained direct client communication, covering both technical and strategic discussions.
- Independently handled project management and delivery - consistently on time and to spec.
- Managed small engineering teams and collaborated across roles when needed.
- Personally drove client acquisition, sales conversations, and basic marketing efforts as a freelancer.
- Specialized in scalable, maintainable code and user-focused solutions.
My main workplace. All gaps between other jobs in my experience were filled with freelance.
Senior Full-Stack JavaScript Engineer & Product Architect
Thentia
Mar 2024 - Sep 2024
Toronto, ON, Canada · Full-time · Remote
Joined full-time to lead the development of a new strategic product line - entrusted to own it end-to-end from day one. Acted in a cross-functional capacity, covering roles of a senior engineer, product designer, and fractional CTO.
- Architected and implemented a scalable frontend and backend system.
- Collaborated directly with the VP of Design to shape the user experience and product vision.
- Oversaw technical scoping, UX, planning, and delivery in a startup-like environment.
- Worked closely with DevOps, engineers, and internal stakeholders to coordinate environments and infrastructure.
- Supported junior developers and led by example through code reviews and technical coaching.
- Ensured high-quality delivery of complex features, including integrations and data migrations.
Senior Frontend Developer
Thentia
Sep 2019 - Nov 2022
Toronto, ON, Canada · On-demand · Remote
Worked on an on-demand basis contributing to key frontend systems that required advanced expertise. Despite a team of 100+, I was the only developer able to implement critical frontend infrastructure.
- Developed complex UI components and scalable architecture for enterprise systems.
- Helped maintain and evolve the core frontend codebase used across Thentia’s regulatory products.
- Collaborated with in-house teams to meet high accessibility, security, and scalability standards.
- Trusted to work independently with minimal supervision while meeting strict deadlines.
- Contributed to core products during a high-growth phase.
- Thentia raised over $59M in funding and is valued at around $100M now. I played a key role in the development of nearly all of their current revenue-generating products, and I was solely responsible for the company’s main website and blog.
Skills
Core Skills
React, Next.js, Node.js, JavaScript, TypeScript, REST API, GraphQL, Clouds, Nest.js, Tailwind CSS, Material UI, UX/UI, Git.Leadership & Business Skills
C-level collaboration (CEO, VP, Product), Fractional CTO for funded startups, Product strategy & roadmapping, Team mentorship & hiring, Cross-functional communication (Dev, Product, Design, Marketing).Industries
GovTech, EdTech, FinTech, HealthTech, Finance & Investments, E-Commerce, Entertainment, Real Estate, Travel & Aviation, Food & Beverage, HR Tech, Online Safety, Crypto.Specializations
Frontend, Backend, Full-Stack, JAMstack, AI Integration, UI/UX, Startup, MVP, Cloud, SaaS, API Integration, Responsive Design, Cross-Platform, Mobile, Automation.
Technical Skills
Frontend: React, React Native, Angular, Vue, Next.js, Nuxt.js, Remix, Astro, Gatsby, Svelte, TypeScript, JavaScript, Redux, Zustand, Mobx, Recoil, Context API, React Query, HTML5, CSS3, SASS/SCSS, PostCSS, WebSocket, Socket.io, WebRTC, SSG, SSR, ESLint, Husky, Zod, Yup, react-hook-form, Formik.
Backend: Node.js, Nest.js, Fastify, AWS, Google Cloud, Azure, Supabase, MongoDB, PostgreSQL, TypeORM, Prisma, RabbitMQ.
API: REST, GraphQL, Apollo, Express, Axios, Stripe, Hubspot, Cloud APIs.
UI Libraries / Design Systems: Tailwind CSS, ShadCN, Radix UI, Material UI (MUI, MUI X), Magic UI, Bootstrap, Ant Design, Chakra UI, Mantine, Storybook, Design Systems, Figma in Code, Code in Figma.
Mobile UI: NativeBase, React Native Paper, React Native Elements (RN Elements).
Cross platform: Ionic, Electron, GlueStack.
Bundlers / Build Tools: Vite, Webpack, Gulp, Rollup, Turbopack.
Deployment / Hosting: Vercel, Netlify, Heroku.
Headless CMS: Strapi, Contentful, Sanity, Storyblok, GraphCMS, Netlify CMS.
Automation: make.com, n8n.
AI / Tools: OpenAI, ChatGPT, Replit, Cursor AI, Lovable, Vercel v0, Figma to Code.
Cross-platform Frameworks: Ionic, Electron.
Crypto / Web3: Solana, Wagmi, Viem, Hardhat, OpenZeppelin, Web3.js, Blockchain.
Education
Bachelor of Engineering (BEng), Aerospace Engineering
National Aviation UniversitySep 2007 – Jun 2011
Kryvyi Rih, Dnipropetrovsk, Ukraine
Languages
English: Advanced
Ukrainian: Native
Russian: Native