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Denis Kukhtin
Senior Frontend / Full-Stack Engineer · Agentic Development
Kharkiv, Ukraine · Remote or on-site
[open contact info](look above in the "contact info" section) Telegram @aFriendOfYours [open contact info](look above in the "contact info" section)

Updated Senior frontend / full-stack engineer with 7 years of commercial experience building
September 2026
production web applications from architecture to release. Using AI coding agents daily
since 2025 to speed up development and strengthen quality control: built a workflow where
Claude Code and Codex assist with implementation while I own the architecture, specs and
final code review, backed by isolated worktrees, independent AI review and automated
validation across multiple product repositories. Strong in React, Next.js and TypeScript;
backend with Node.js, Fastify and PostgreSQL.

How the AI-driven development process works
I own the plan, the spec, the architecture and the final review; AI coding agents work in an isolated worktree,
and an independent agent adds a second review pass before my code review and merge.

Experience
Sep 2024 – Sep 2026 Senior Frontend / Full-Stack Engineer at FREITTY, freitty.com ↗
Remote Logistics and transport platform. Sole frontend engineer alongside one backend developer; owned
frontend architecture, standards, production evolution and cross-project contracts.
AI-assisted delivery Since 2025, used an AI-assisted workflow to speed up delivery of all frontend work, including the
public site freitty.com ↗: I specified and reviewed every portal, cabinet and design-system task, paired
with Claude Code and Codex on implementation, and added AI review and automated validation as
extra quality gates before my own code review.
Turned architecture, naming, API and testing conventions into binding agent context (AGENTS.md,
skills, spec templates), so AI-assisted code met the same standards as hand-written code.
Architecture Built and evolved a production Next.js/TypeScript portal architecture with SSR/SSG, Redux Toolkit
and styled-components.
Architected a separately published Client Cabinet module with host-owned auth, navigation, API
adapter and capability boundaries.
Developed a design-system monorepo with versioned theme, UI Kit and utilities packages distributed
through GitHub Packages.
Built the UI motion layer with Motion for React (formerly Framer Motion): a shared provider with lazily
loaded LazyMotion features, reusable motion primitives for sections, table rows and footers, and
AnimatePresence transitions across booking flows, modals, tables and chat.
Defined reusable patterns for complex multi-step flows (state ownership, data loading, validation,
recovery) and responsive layouts down to 320px, safe areas and dark themes.

1/4

Denis Kukhtin Senior Frontend / Full-Stack Engineer · Agentic Development

Payments & backend Designed payment integrations across client and server: Stripe card and Google Pay payments for
orders, invoices and top-ups, plus token-based Authorize.Net Accept Hosted payment forms, with
status listeners and recovery states.
Implemented Next.js API endpoints for NextAuth with Google sign-in, email delivery and partner forms,
plus routing and image proxies, with typed contracts against the core API.
Created transactional email infrastructure with React Email: reusable responsive templates, in-app
previews and a sending endpoint.
Built realtime order chat on SignalR with automatic reconnect and room rejoin, plus background sync
of notifications with unread counts and pagination.
Integrated localization infrastructure (next-i18next), analytics and consent-aware attribution behind
typed adapters, and sanitized user-supplied HTML with DOMPurify.
Maps & media Built map experiences for the logistics product: hub and location maps on Mapbox GL and Google
Maps, route rendering with Leaflet Routing Machine, Google Directions and encoded polylines, an
OSRM routing proxy, and a lazy-loaded driver view with arrival time.
Handled user media in the browser: HEIC and TIFF conversion, avatar cropping and in-app PDF
preview.
Performance & search Optimized Core Web Vitals (LCP, CLS, INP) against PageSpeed Insights and Lighthouse via code
splitting by route, lazy loading, bundle and font optimization.
Code-split the RTK Query data layer: the booking API slice loads on demand, its reducer and
middleware are injected at runtime through a reducer manager and RTK dynamic middleware, with
tuned cache lifetimes and refetch on focus and reconnect.
Made pages discoverable by search and AI answer engines (SEO/GEO): typed, tested JSON-LD
builders that parse hub addresses, coordinates and operating hours into Schema.org structured data,
injected server-side with XSS-safe serialization.
Testing & CI/CD Built an in-app Playwright runner for the dev environment: E2E suites launch from a dev-only panel in
silent, headed or UI mode, with live SSE logs and a real-time browser view via Xvfb/noVNC behind
nginx, restricted to trusted hosts.
Designed the E2E infrastructure: a TypeScript AST build transform that injects stable data-e2e
selectors, guest/authenticated Playwright projects with reusable sessions and booking/order-flow
suites, plus Jest/Testing Library unit tests.
Set up CI/CD on GitHub Actions: parallel lint, Jest and build checks, and dev/prod pipelines that build,
ship over SSH, restart the app under PM2 and validate/reload nginx with diagnostics; Husky git hooks.

Skills
Agentic engineering AI-assisted development, LLM coding agents (Claude Code, OpenAI Codex), multi-agent orchestration,
spec-driven development, prompt and context engineering (AGENTS.md, skills, hooks), MCP
(Context7), AI code review, model/effort routing, Git worktree isolation
Frontend TypeScript, JavaScript, React, Next.js, Vite, HTML, CSS, SSR/SSG, Core Web Vitals, SEO, responsive
UI, accessibility
Architecture & state Redux Toolkit, RTK Query, TanStack Query and Router, MobX, Atomic Design, modular architecture,
Turborepo and pnpm monorepos
UI engineering styled-components, Tailwind CSS, Motion (Framer Motion), Storybook, Chromatic, Radix UI, tsup,
design tokens, component libraries
Backend & APIs Node.js, Fastify, PostgreSQL, Prisma, REST APIs, OpenAPI, Zod, Better Auth, Docker, Docker Compose
CI/CD & infra GitHub Actions, GitHub Packages, SSH deploys, PM2, nginx, Husky, Linux servers
Integrations Stripe, Authorize.Net, Google Pay, SignalR, SSE, NextAuth, next-i18next, DOMPurify, React Email,
Mapbox GL, Google Maps, Leaflet, OSRM, third-party APIs, typed adapters
Quality Jest, Vitest, React Testing Library, Playwright, Jasmine, ESLint, Prettier, CI quality gates
Other Angular, NgRx, RxJS, Akita, Astro, Alpine.js, PWA, Workbox, IndexedDB

2/4

Denis Kukhtin Senior Frontend / Full-Stack Engineer · Agentic Development

Selected projects
AI engineering platform, in Multi-Agent Engineering Framework
daily use
Designed a lead/worker agent workflow: I plan and approve each task, and short-lived Claude Code or
Codex workers help with implementation in isolated Git worktrees across multiple repositories.
Built taskctl, a tested Node.js orchestration CLI with a task state machine, dry-run/execute mutations,
locks, crash recovery and diff-fingerprinted validation receipts.
Enforced quality gates: independent spec review before dispatch, cross-model code review,
automated lint/type/test validation and an explicit human commit gate.
Routed tasks across model and reasoning-effort tiers to balance cost, speed and depth; fed agents live
library docs via Context7 over MCP.
Maintained a decision log that turns observed agent failure modes into enforced process rules.
Independent full-stack Mirror Platform
project Built a TypeScript/Turborepo foundation spanning Next.js, Vite and Fastify applications.
Implemented Better Auth identity, guest/user carts, cart merge and server-authoritative checkout.
Designed atomic order placement with idempotency, immutable snapshots, inventory reservations,
concurrency protection and transactional outbox records.
Used PostgreSQL, Prisma, Zod, OpenAPI and generated TypeScript API clients with unit/integration
coverage.
Production, FREITTY Client Cabinet & Design System
ecosystem
Created a standalone React application and publishable module embedded in a Next.js host.
Defined auth, routing, logout, API adapter and capability boundaries without exposing host tokens.
Built dashboard and orders experiences with table, list and grid views and persisted user settings.
Maintained pnpm packages for theme, UI components and utilities with typed exports and semantic
tokens: responsive tables, charts, calendars, date ranges, filters, cards and layout components.
Used Radix UI, Storybook, Chromatic and tsup for accessibility, documentation and controlled
releases.
Designed the components and their APIs myself; agents contributed to components, stories and
release prep, and every change passed AI review and my own code review.

Earlier experience
Apr 2024 – Jul 2024 Frontend Developer at SkillUp
Full time, Kharkiv. Travel and parcel delivery platform.
Built responsive product interfaces with Astro, Alpine.js, Tailwind CSS and TypeScript.
Translated product requirements into reusable components and production-ready UI.
Stack Astro, Alpine.js, Tailwind CSS, TypeScript
Aug 2023 – Apr 2024 Frontend Developer, React under NDA
Full time, Kharkiv. Multiplatform medical education product.
Built TypeScript/React components for Windows, macOS, Android and iOS product surfaces.
Worked within a microservice architecture using Atomic Design, Storybook and Jest.
Stack React, TypeScript, Storybook, Jest, Atomic Design, microservices
Mar 2023 – Aug 2023 Frontend Developer, Next.js under NDA
Full time, Kharkiv. E-commerce application.
Implemented reusable TypeScript components and customer-facing product functionality.
Stack Next.js, React, TypeScript

Sep 2021 – Mar 2023 Frontend Developer, Angular under NDA
Full time, Kharkiv. Pharmacy operations platform.
Web application supporting patient workflows from reception through recovery, including documents and
medication management.
Designed and delivered Angular product components and new business functionality.

3/4

Denis Kukhtin Senior Frontend / Full-Stack Engineer · Agentic Development

Integrated SignalR for realtime workflows.
Developed a reusable component library distributed as an npm package.
Stack Angular, TypeScript, RxJS, NgRx, Akita, SignalR, npm component library
May 2021 – Sep 2021 Frontend Developer, Angular under NDA
Full time, Kharkiv. Remote device management.
Migrated existing code and implemented device settings and remote-control features.
Added Jasmine/Karma unit coverage for new and migrated functionality.
Stack Angular, TypeScript, Jasmine, Karma

Dec 2020 – Mar 2021 Frontend Developer, React under NDA
Part time, Kharkiv. Offline barcode printing.
Built PWA capabilities with Google Workbox.
Used IndexedDB for offline synchronization, authorization and barcode printing.
Stack React, PWA, Workbox, IndexedDB

Sep 2020 – Dec 2020 Frontend Developer, React under NDA
Part time, Kharkiv. Inventory and barcode management.
Introduced TypeScript and delivered reusable components, unit tests and product improvements.
Stack React, TypeScript, unit testing
Aug 2020 – Mar 2021 Frontend Developer, React under NDA
Part time, Kharkiv. Document and request workflow platform.
Built components and unit tests for document exchange, vacation requests, events and travel booking.
Integrated DocuSign for document-signing workflows.
Stack React, MobX, DocuSign, unit testing

Mar 2019 – Aug 2020 Freelance Frontend Developer
Websites for small businesses.
Built responsive business-card websites and landing pages with cross-browser HTML/CSS.
Stack HTML, CSS

Education
Feb 2025 V. N. Karazin Kharkiv National University
Jun 2005 Kharkiv Machine-Building College Economist

Languages
English B1+ Intermediate
Russian Native
Ukrainian Native

4/4