Вадим

Vadym Melnychenko
Senior Frontend Developer — React / Next.js / TypeScript
Castel San Giovanni (Piacenza), Italy · ~1h from Milan · Authorized to work in Italy — no visa sponsorship required
[відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · github.com/melnicenkovadik
Open to: Hybrid (Milan) · Remote · On-site (Milan / Emilia-Romagna)

PROFESSIONAL SUMMARY
Senior Frontend Developer with 9+ years building production web applications in fintech, payments, blockchain, AI,
and SaaS. Deep expertise in React, Next.js, and TypeScript: architecting scalable, modular frontend platforms,
building accessible design systems shared across teams, integrating LLM capabilities into production products, and
leading teams of up to 6 developers. Strong ownership of features end-to-end — from technical design and code
reviews to unit, integration, and E2E testing and CI/CD. English C1, Italian A2.
CORE SKILLS
Frontend: React, Next.js (SSR / App Router, code splitting, lazy loading), TypeScript, JavaScript (ES6+), TanStack Query (React
Query), Zustand, Redux Toolkit, MobX, Recoil, GraphQL (Apollo), RESTful APIs, WebSockets, Zod (schema validation), RxJS,
Microfrontends
Design systems / UI: Tailwind CSS, headless component libraries (Radix UI, shadcn/ui), Storybook, Material UI, Chakra UI,
styled-components, SCSS, CSS Modules, Figma, accessibility (a11y)
Build & architecture: Vite, Webpack, Nx / Turborepo monorepos, Atomic Design, design patterns, modular and scalable frontend
architecture
Testing: Vitest, Jest, React Testing Library, Cypress, Playwright (E2E), unit / integration / E2E test suites
CI/CD, cloud & observability: GitHub Actions, GitLab CI, Docker, AWS, Vercel, Sentry (error monitoring)
Performance: Web Vitals, Lighthouse, code splitting, lazy loading, caching (CDN, memoization)
AI & LLM: OpenAI API, Claude API, LangChain, RAG pipelines, prompt engineering, vector databases (Pinecone, Weaviate)
Blockchain / Web3: ethers.js, web3.js, WAGMI, Hardhat
Also: Node.js / Nest.js, PostgreSQL, MongoDB, Agile / Scrum
PROFESSIONAL EXPERIENCE
Trustyfy — Senior Software Engineer, Frontend
May 2025 – Present · Fintech / payments (crypto banking cards)
• Architected and built the customer-facing web application end-to-end in React, Next.js, and TypeScript:
onboarding flows, card management, transaction history, and real-time balance tracking over REST and
WebSocket APIs, with Zod-validated forms and Sentry error monitoring in production.
• Built the internal backoffice platform with role-based access control, compliance dashboards, transaction
monitoring, and multi-step approval workflows for financial operations.
• Designed a shared, accessible design system and modular frontend architecture used across both applications,
enforcing coding standards through code reviews and shortening feature delivery.
ZeuZ — Full Stack Engineer (Contract)
Dec 2024 – Jul 2025 · Crypto trading platform
• Sole developer: built a fully functional crypto trading platform with multi-account support, cross and isolated
margin trading, and detailed account statistics.
• Integrated Web3 wallets (MetaMask, Trust Wallet) for secure, private trading without traditional exchange
onboarding.
• Designed and user-tested the trading UX end-to-end.
Harvey — Software Engineer (Contract)
Aug 2024 – Apr 2025 · AI platform for the legal industry, 1000+ customers in 60+ countries
• Built UI for AI-powered legal tools: document-analysis workflows and LLM-driven chat interfaces over complex
legal data.
• Integrated large language model capabilities into the product frontend, working with AI and backend teams to ship
responsive, real-time AI-assisted features.
• Contributed to the platform's design system and component library, improving development velocity and UX
consistency across product surfaces.
Optimism Foundation — Senior Frontend Developer (Contract)
Jul 2024 – Nov 2024 · Blockchain project (under NDA): secure crypto wallet interfaces and DeFi
• Implemented decentralized authentication, encryption, and token integration with backend and security teams.
• Optimized UI components for scalability and speed in a crypto environment.

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PROFESSIONAL EXPERIENCE continued
Prof-IT Blockchain — Frontend Team Lead / Full-Stack Web3 Developer
Jan 2023 – Jul 2024
• Led a team of 6 developers building a secure crypto wallet with zero security breaches; improved page load times
~25% through Next.js performance optimization (code splitting, lazy loading, caching).
• Delivered Chrome extensions that strengthened blockchain integration and increased user adoption.
• Established code-review processes and weekly knowledge-sharing sessions; sole developer on the Patex
ecosystem (reusable components, Jest / Cypress test suite, multiple feature launches that drove revenue
growth).
Coinbase — Senior React Developer (Contract)
Mar 2022 – Jan 2023
• Integrated advanced analytics and real-time data visualizations into internal tooling, reducing monitoring
response times ~20%.
• Optimized Redux state management, reducing load times; built content-management tooling that cut
administrative workload.
Nimbus Platform — Frontend Developer
Feb 2021 – Mar 2022
• Delivered optimized GraphQL APIs in a Next.js codebase with teams across Europe and North America, cutting
data-fetch times ~30%.
• Wrote unit tests, refactored components, and improved documentation and onboarding.
INC4 — Frontend Developer
Jan 2017 – Jan 2021
• Led blockchain application development for Ambrosus, contributing to successful ICOs and platform launches.
• Modernized legacy React applications, reducing technical debt; built responsive landing pages that raised
engagement and conversion.
• Mentored junior and mid-level developers through code reviews and weekly knowledge-sharing, reducing
onboarding time ~40%.

KEY ACHIEVEMENTS
• Built a fintech / payments platform from scratch (Trustyfy): customer-facing app and backoffice, one shared design
system.
• Integrated LLM capabilities into a production legal-tech platform (Harvey) used by 1000+ enterprise customers.
• Shipped crypto wallets and a trading platform with zero security breaches across multiple Web3 products.
• Built and maintained reusable component libraries and design systems (Storybook + Figma), improving
development efficiency ~30%.
• Set up automated CI/CD pipelines (GitHub Actions / GitLab CI) and unit / integration / E2E test suites,
accelerating release cycles.
EDUCATION
Master's degree in Computer Systems Analysis — National University of Life and Environmental Sciences of
Ukraine, 2012–2018
Relevant coursework: Software Engineering, Data Structures, Algorithms, Database Systems
LANGUAGES
Ukrainian (native) · Russian (fluent) · English (C1, advanced) · Italian (A2, basic)

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