Дмитро

Dmytro Tymoshenko
Frontend Developer (React.js / Next.js / TypeScript) — AI-Powered Interfaces
[open contact info](look above in the "contact info" section) | github.com/kenmaqqe | [open contact info](look above in the "contact info" section) | kenmaqqe-portfolio.vercel.app | Zhytomyr,
Ukraine · Open to Remote

SUMMARY
Frontend Developer with 2+ years of commercial experience building performance-first, scalable web applications with React.js,
Next.js, and TypeScript. Combine solid engineering fundamentals (component architecture, state management, REST API
integration) with practical experience integrating LLM APIs into production interfaces, including the Anthropic Claude API. Treat
AI tooling (Cursor, Claude, GitHub Copilot) as a force multiplier for engineering velocity — not a substitute for it — using it to
speed up testing, debugging, and iteration while maintaining full ownership of architecture and code quality.

TECHNICAL SKILLS
Frontend: React.js, Next.js (App Router, SSR, SSG, RSC), TypeScript, JavaScript (ES6+), HTML5, Canvas
AI & LLM Integration: Anthropic Claude API, Streaming Responses, Prompt Engineering, MCP (Model Context Protocol)
State & Data: Redux Toolkit, Zustand, React Query, Context API, WebSockets
APIs: REST API, Axios, GrammyJS (Telegram Bot API)
Styling & Testing: Tailwind CSS, SCSS, BEM, Figma, Jest, React Testing Library
DevOps & Practices: Git, Vercel, CI/CD, Web Accessibility (a11y), SEO, Agile/Scrum

AI DEVELOPMENT EXPERIENCE
• Anthropic Claude API: built Bully Chat, a personal AI chat project with streaming responses via the Claude API, optimistic UI
updates, persistent chat history, and performance-first architecture. Hands-on with async streaming, token management,
and error states end-to-end.
• Use AI-assisted tools (Cursor, GitHub Copilot) to accelerate routine development tasks — boilerplate, test generation,
debugging — freeing up time for architecture and code quality work.
• Apply Claude and ChatGPT as engineering aids for design discussions, debugging strategy, and code review augmentation —
final architectural and implementation decisions remain mine.
• Prompt engineering: structure system and user prompts for LLM APIs; familiar with chain-of-thought, few-shot patterns,
and reliable JSON output formatting.
• Anthropic Artifacts & MCP: confident understanding of the Artifacts concept and Model Context Protocol as an emerging
standard for LLM-tool integration — actively following developments.
• Built an AI-powered SaaS interface for a freelance client — improved Lighthouse score from 65 to 88 and reduced runtime
errors by roughly 80% via structured error boundaries.

EXPERIENCE
Frontend Developer — T+ Market (E-Commerce Platform) Dec 2024 – Present
• Engineered a scalable React.js/Next.js component library integrating 5+ REST APIs via Axios and custom hooks, eliminating
technical debt by refactoring 15+ legacy components and cutting code duplication by ~25%.
• Architected a multi-level, SSR-compatible product filtering system with URL-persisted state, reusable across product
categories, supporting shareable links and full browser navigation.
• Leveraged AI-assisted tooling (Cursor, Claude) to accelerate test generation and debugging cycles, enabling faster, more
thorough code reviews within a 10+ person engineering team.
• Enforced critical-path test coverage with Jest/RTL, supporting reliable bi-weekly releases with zero critical regressions in a
fast-moving Agile/Scrum environment.
Freelance Frontend Developer Feb 2024 – Nov 2024
• Delivered production web applications end-to-end as sole developer — React.js, Next.js App Router, TypeScript — from
Figma handoff to Vercel deployment, across single-client engagements.
 • Engineered a performance-optimized, mobile-first website for top-tier content creator Dmytro Tyutyun (200K+ YouTube
subscribers, dmytrotyutyun.com), built to withstand traffic spikes of 200-500+ concurrent visitors during high-visibility show
announcements. Delivered dynamic event scheduling, real-time ticket availability, UA/EN multilingual support, and analytics
tracking — Lighthouse score 90+.
• Built a Telegram bot integration (GrammyJS) for automated lead delivery, saving the client 5+ hrs/week of manual work.
Frontend Developer — Baza Aug 2023 – Feb 2024
• Translated 20+ Figma designs into reusable, pixel-perfect React.js/TypeScript components, implementing animations,
transitions, and complex UI interactions with full cross-browser compatibility.
• Enforced BEM methodology and semantic HTML5 across the codebase, reducing long-term technical debt and improving
maintainability.
• Participated in peer code reviews within a 3-developer team, contributing to and helping enforce web accessibility (a11y)
standards.

PROJECTS

Bully Chat — AI Chat Companion (Personal Project)
Next.js · TypeScript · Anthropic Claude API · Zustand · Tailwind CSS
bully-chat.vercel.app · github.com/kenmaqqe/bully-chat
• Sole developer. Built an AI chat app featuring a single custom fictional character, powered by the Anthropic Claude API with
streaming responses, optimistic UI, and persistent chat history.
• Hands-on experience with LLM API integration: token handling, async streaming, prompt structuring for character
consistency, and error boundary handling.

Frontend Error Observatory — Dev Tool
React · TypeScript · Vite
frontend-error-observatory.vercel.app · github.com/kenmaqqe/frontend-error-observatory
• Interactive dev tool for triggering, catching, and visualizing runtime errors — built for junior developer onboarding and
debugging education.

Contrlve Game — Fan Web Game
Next.js · TypeScript · React
contrlve-game.vercel.app
• Built a turn-based fan game inspired by the YouTube show “Contrlve,” featuring complex state logic and frame-accurate
CSS/JS animations.
• Drove 100+ visitors and 200+ page views organically in the first days, drawing public recognition from the show's SMM
team.

EDUCATION
Zhytomyr Technological College — Diploma in Computer Engineering 2019 – 2023
Relevant coursework: Algorithms & Data Structures, Software Engineering, OOP, Computer Systems Architecture

LANGUAGES
Ukrainian — Native · English — Intermediate (B1+), confident in technical discussions