Олександр

Alexander Kutsenko
Senior Front-end / Full-stack Developer · React · TypeScript · Node.js
Kyiv, Ukraine · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · github.com/Alexkutsenko95 · [open contact info](look above in the "contact info" section)
kutsenko95 · nextcv-pi.vercel.app

SUMMARY

Front-end-led full-stack developer with 9 years of commercial experience in React and TypeScript, building and
optimizing high-load web applications — interfaces that stay responsive under a constant stream of real-time
data, pixel-perfect from Figma. Modernizes legacy front-ends onto current React while the product stays in
production. Built logistics and fleet-management platforms rendering large live geodata sets, and real-time
clients kept in sync with the back end over WebSockets. Most recently shipped 8 real-time game titles to
production on React, TypeScript, PixiJS and GSAP, together with the shared component and business-logic
libraries behind them. On the back end: Node.js, Express and Socket.IO in production work; NestJS and
PostgreSQL in Bidstream, a real-time auction platform with tests, Docker and CI.

TECHNICAL SKILLS

Core JavaScript (ES6+), TypeScript, HTML5, CSS3, SCSS
Front-end React (Hooks, Context), React Native, Redux, Redux-Saga, Zustand, MobX, Next.js
Real-time & graphics PixiJS, GSAP, WebSockets, deck.gl, OpenLayers
Back-end & APIs Node.js, NestJS, Express, PostgreSQL, Drizzle ORM, Socket.IO, REST APIs, Sequelize,
Mongoose
Build & delivery Vite, Webpack, Turborepo, Docker, GitHub Actions, npm, ESLint, Prettier, Cloudflare Pages
UI styled-components, Material UI, React-Bootstrap, React Table, Formik, React Hook Form,
responsive layouts (desktop and mobile), pixel-perfect implementation from Figma
Performance performance optimization, profiling (Chrome DevTools, React Profiler), memoization,
virtualization, code splitting, bundle analysis
Testing Jest, Vitest, React Testing Library, Supertest, Puppeteer (browser-driven suites)
AI coding tools Claude Code, Codex
Workflow Git, Bitbucket, Jira

EXPERIENCE

Senior Front-end Developer — Enjoy Gaming Apr 2024 – Sep 2026
React TypeScript Zustand PixiJS GSAP Vite WebSockets

Real-money gaming provider, regulated by the Isle of Man Gambling Supervision Commission. Team of 12.
Shipped 8 live game titles to production.
Tournaments — built the entire front end solo: a React 19 promo product layered over the whole game line, where
players compete inside a single title or across every game at once. Profiled render performance with the React Profiler
and optimized against those measurements.
Extracted the shared foundation behind the line: a React component library that reduced each new game to theming
and configuration, and a standalone business-logic library used by every title — bet placement and validation, payout
calculation and round state handling.
Animated game scenes with GSAP and PixiJS — wheel spins, lucky-number and multiplier reveals, win sequences —
rendered over the live video stream.
Implemented real-time synchronization with the game server over WebSockets, keeping the client — betting window,
results, payouts — consistent with the live round under packet loss and reconnects.
Profiled and optimized the render loop — per-frame allocations, texture memory and scene complexity — holding 60 fps
under the live data stream, with quality scaled down on weak devices.
Owned client-side state architecture on Zustand and migrated the build pipeline to Vite.
Reviewed code and mentored teammates across the front-end team throughout, keeping the shared libraries refactored
as the individual games diverged.
Front-end Developer — Inoxoft Apr 2021 – Mar 2024
React Redux Redux-Saga TypeScript Webpack deck.gl OpenLayers
Software outsourcing company; worked on freight-delivery and fleet-management platforms for the UK market.

Delivered logistics applications on React + TypeScript for freight deliveries across the UK — from requirements to
production support, working directly with the clients; built the UI responsive for desktop and mobile, pixel-perfect to the
Figma designs.
Built interactive map interfaces for route planning, fleet and shipment tracking using deck.gl and OpenLayers, and
optimized them to render large sets of live geodata without dropping frames — profiling re-renders, memoizing selectors
and throttling live updates.
Implemented complex asynchronous flows with Redux-Saga — long-running requests, retries and live tracking streams
— and delivered a second logistics product for a different client, under NDA.
Modernized inherited legacy React code as a routine part of the work: class components rewritten to hooks, expensive
renders memoized, and a clear split between container and presentational components — refactoring in place, without
pausing feature delivery.
Ran code review and mentored junior developers as a constant part of the role; took part in estimation and planning.

Earlier experience — Front-end / Full-stack Developer May 2017 – Mar 2021
React React Native Redux Redux-Saga Redux-Thunk MobX Next.js Express Socket.IO Jest
Zazmic, ORTY IO, JS Dynamics, freelance, Onnisoft, Starthubit and Big Data Hush — product and outsourcing teams where the
React and Node.js foundation was built.
Shipped web and cross-platform mobile interfaces from a shared React / React Native codebase, including offline and
error states on mobile.
Built the player-facing client of a licensed online casino running third-party game providers — lobby, betting UI and
account screens — plus the back office it was operated from, and integrated a sports provider's live match streams on
both sides: in-play betting for players, and the same feed in the back office, where a match could be blocked from the
site.
Delivered full-stack features on React with a Node.js / Express back end and real-time updates over Socket.IO, covered
the front-end with Jest unit tests, and maintained and refactored legacy front-ends across product and outsourcing
teams alongside feature work.

SELECTED PROJECTS

Bidstream — real-time auction platform, personal project github.com/Alexkutsenko95/bidstream
NestJS PostgreSQL Drizzle ORM Socket.IO React 19 TanStack Query Docker GitHub Actions
Full-stack TypeScript monorepo: a NestJS API on PostgreSQL and a React client kept in step over WebSockets.
Bids are a single conditional UPDATE, so competing bidders serialise on the row lock with no read-modify-write
window; a test races 40 concurrent bidders and checks the history stays gap-free and strictly increasing.
Idempotency keys and a transaction-scoped advisory lock make retried bids safe — added after the test suite caught
concurrent retries being rejected. pg_notify inside the bid transaction fans committed events out across API instances
without Redis, verified with two instances on one database.
Shared zod contracts for API and client, integer-cent money, anti-sniping in SQL, httpOnly sessions and rate limits; 74
tests against a real PostgreSQL, and CI that builds and boots the whole Docker stack.
Reel Five — 5×3 slot machine, personal project reel-five.pages.dev
React 19 TypeScript PixiJS 8 GSAP Zustand Vite Vitest

PixiJS renders the reels, React owns the interface, and a single zustand store is the only source of truth: the reels never
touch the balance, they replay a result the store has already decided. Reel stop is a state machine with velocity kept
continuous from spin to settle.
Reel strips tuned by simulation to a 95.97% RTP over 1,000,000 spins; 118 tests in Node, jsdom and a real Chrome —
the browser suite caught two defects the other two could not reach.

Penalty & Free kick — two football games on one kutsenko-penalty.pages.dev · kutsenko-free-kick.pages.dev
engine, personal projects
React 19 TypeScript PixiJS 8 Zustand Vite Vitest Cloudflare Pages

Two games on one shared source layer: physics, goalkeeper, input model, layout and localization live in one place.
The ball flies by numerical integration — drag, Magnus lift, spin decay — and the launch is solved as a boundary-value
problem, so the player still aims at a point while the flight stays physical. The keeper is bounded by hand speed; 126
tests, including a search proving every generated level is beatable.

EDUCATION & LANGUAGES
National Transport University (NTU) — PhD, Software Engineering · 2018 – 2024
Kyiv State Maritime Academy (KDAVT) — MSc, Software Engineering · 2016 – 2018
GoIT — Java SE / Java EE course · 2015 – 2016
Ukrainian — native · English — B2 (Upper-Intermediate)