makson

React Native & Frontend Developer

Розробник React Native + Frontend з більш ніж 2,5 роками практичного комерційного досвіду розробки мобільних Web3 гаманців та HTML5 ігор. 

Минулого року запустив продакшн-функції багатоланцюгового криптогаманця (React Native + TypeScript) для клієнта Web3 з угодою про нерозголошення для Ethereum, Polygon, Arbitrum, Bitcoin (Lightning + он-чейн) та додаткових мереж EVM — повний потік надсилання/отримання з роздільною здатністю UMA/LNURL, абстракція облікового запису ERC-4337 (Safe + bundler + paymaster), криптоматаматика BigInt, мнемоніка BIP39, біометрична в'язка ключів, шаблони інтеграції гаманців EIP-1193 / EIP-695 / EIP-2255. 

Щоденний досвід: строгий режим TypeScript, React + Next.js, React Native (Expo 54, Reanimated v4, Skia, Rive, FlashList), Zustand + MMKV, TanStack Query, ethers.js, інтеграція MetaMask, EAS Build CI/CD, Jest + RTL + Maestro. 

Також 1 рік роботи над Pixi.js + Spine 2D + GSAP над ігровим автоматом для iGaming (клієнт NDA) — впевнене володіння власними ігровими двигунами, FSM, механізмами послідовностей, сигнальною шиною, пулінгом об'єктів. 

Відкриті вакансії: криптогаманець React Native, Web3 фронтенд (React + ethers/viem), DeFi панелі інструментів, віддалена робота в ЄС/Великій Британії/США, контракт або повний робочий день. 

Базуюсь в Італії (UTC+2), англійська мова B1.


Experience: 2 years

Yearly salary: $40,000

Hourly rate: $25

Nationality: 🇺🇦 Ukraine

Residency: 🇺🇦 Ukraine


Experience

React Native Developer
TenThousand
2025 - 2026
Contributed to a production multi-chain crypto wallet (React Native, TypeScript) for an NDA Web3 client across Ethereum, Polygon, Arbitrum, Plasma, Spark, and Bitcoin (Lightning + on-chain). Developed the full send/receive transaction flow: UMA/LNURL address resolution, dynamic fee estimation (15s refresh), sanctioned-address compliance, biometric confirmation, and full error handling. Implemented reactive balance aggregation across 7 networks using TanStack Query with MMKV caching, stale-while-revalidate, and AppState-aware polling. Migrated crypto math using BigInt and BigNumber.js across fee estimation, fiat conversions, and Wei/Satoshi parsing — eliminated precision-loss bugs. Integrated ERC-4337 account abstraction (Safe contracts, bundler, paymaster) for sponsored gasless EVM transactions. Built validation utilities, a chain-aware QR code component, BIP39 mnemonic management, biometric keychain, and screen-recording protection; integrated Firebase (FCM + Remote Config) and Sentry. Worked with Reanimated v4, Skia, Rive, FlashList, Zustand (10 stores with MMKV persistence), Expo Router, and i18next; maintained CI/CD on GitHub Actions + EAS Build with Jest + RTL and Maestro tests.
Frontend Developer
TenThousand
2025 - 2025
Contributed to production HTML5 slot games (Pixi.js, NDA iGaming client) implemented gameplay features and bug fixes under a senior lead on the client's proprietary slot framework (finite state machine, sequence/step engine, signal bus, object pools). Built the bonus flow where special symbols stick to reels, trigger respins, and accumulate values into a persistent prize display. Implemented anticipation animation slowing subsequent reels via a dedicated frame component when high-value symbols accumulate. Choreographed coin-collection particle flight to a collector indicator with frame-accurate timing and easing curves. Built win-line playback where each line plays sequentially with per-line payout overlay, followed by an all-symbols celebration frame. Implemented bonus dimmer effect via separate render path for non-bonus symbols; built modal-aware reel fade-out using alpha tweening. Worked extensively with Spine 2D runtime (bones, slot color alpha, attachment swapping) and Pixi.js internals (sprite atlases, render textures, z-ordering).
Freelance Frontend Developer (React)
Self-employed
2022 - 2024
Independent React frontend developer delivering production web applications for 8+ clients across e-commerce, SaaS, and digital agency sectors. Engaged directly with founders and product owners; managed scope, delivery, and post-launch support end-to-end. Built product catalogs and storefronts for e-commerce clients with filters, cart, checkout, and Stripe integration (one-time + subscription). Developed admin dashboards for SaaS clients with complex data tables (sorting, filtering, pagination), role-based access, and bulk operations. Created interactive landing pages with scroll-driven animations (Framer Motion), headless CMS integration (Sanity/Strapi), and SEO optimization — Lighthouse 90+. Refactored a legacy jQuery dashboard into modern React + TypeScript — reduced bundle size by ~40%. Implemented authentication flows (JWT, OAuth, magic links) and reusable component libraries styled with Tailwind CSS, styled-components, or SCSS Modules.

Skills

bitcoin
ethereumjs
firebase
git
nextjs
react
react-native
typescript
web3
english
russian
ukrainian