I’m Nikolai MelnichenkoFront‑end developer based in Lisbon

I build React and TypeScript front‑ends that stay easy to change

Get in touchSee experienceDownload CV PDF, 281 KB
Nikolai Melnichenko
Shared UI
Product screens built on the shared component library and its SCSS/BEM structure, which every app on the platform uses.
Payments
The payment system on a fintech product, and a third-party payment widget set up for each brand.
Performance
Code splitting, lazy loading and bundle analysis, plus Core Web Vitals work on Next.js.
Releases
I run the release cycle for my team and wrote the branching and code-style rules it follows.

Stack

Every day

  • React 19
  • TypeScript
  • JavaScript
  • Next.js
  • SCSS / BEM
  • TanStack Query
  • Vitest
  • Git

Also used in production

  • Angular 20
  • RxJS
  • NgRx
  • Redux Toolkit
  • MobX
  • Emotion
  • react-aria
  • Custom Elements
  • Shadow DOM
  • Nx
  • Vite
  • Webpack
  • Storybook
  • MSW
  • Node.js
  • Express
  • socket.io
  • Zod
  • Docker

From personal projects

  • Playwright
  • Cypress
  • Astro

Used daily, output always reviewed

  • Claude Code
  • GitHub Copilot
  • ChatGPT

Skill showcase

  • Long Walks Atlas with trail filters on the left and the GR11 across the Pyrenees open on the map

    Long Walks Atlas

    A world map of long-distance walking trails, from the Camino de Santiago to Te Araroa, with a prerendered page for every trail in every language.

    • React
    • React Router
    • MapLibre
    • i18next
    Open projectGitHub
  • reflow with the source on the left, the engine's boxes in the middle and the browser's render on the right

    reflow

    A CSS layout engine in TypeScript and a player that replays its layout pass box by box, next to the browser's own render of the same source.

    • TypeScript
    • Svelte
    • CodeMirror
    • Vitest
    Open projectGitHub
  • Aloud captioning a recording, with a settled line and the next one still being heard

    Aloud

    Live captions in the browser. The speech model runs on WebAssembly inside the tab, so the audio never leaves the machine.

    • Angular
    • RxJS
    • WebAssembly
    • IndexedDB
    Open projectGitHub
  • The checkout widget on a demo shop page, offering card, Apple Pay and a saved Visa

    checkout-embed

    An embeddable checkout widget: one script tag puts a payment form on a shop's page, rendered in a shadow root so the shop's CSS cannot reach it.

    • React
    • TypeScript
    • Shadow DOM
    • Nx
    Open projectGitHub
  • The strays map of Lisbon next to a list of found, lost and adoptable animals

    straysDemo

    A map of found, lost and adoptable animals around Lisbon. The backend is still being built, so in the demo msw answers every request inside the browser.

    • React
    • TanStack Query
    • Tailwind
    • Leaflet
    Open projectGitHub

Experience

  1. Jun 2024 – Present

    Current role

    Front-End Developer

    BrainRocket

    On-siteLisbon, Portugal

    • Built product features on the shared UI component library and the SCSS/BEM structure behind it, which every application on the platform uses.
    • Built and maintained per-country versions of the product on top of that library. Layout and content differ from country to country, so each one is its own app in the monorepo.
    • Set up a third-party payment widget for each brand: configuration, loading it on the page and handling its events.
    • Spent over a year on the Angular 20 side of the platform with RxJS, NgRx and SSR over Express, inside an Nx monorepo.
    • Expanded automated test coverage with Vitest, React Testing Library and MSW, and cut page load times with code splitting, lazy loading and bundle analysis.
    • Release Captain for my team, with full ownership of the release cycle. Wrote the release, branching and code-style conventions the team works to.

  2. Nov 2023 – Jun 2024

    Front-End Developer

    REnumber Lab

    ConsultingRemote

    • Led a complete redesign of a marketplace platform on React, Next.js and TypeScript, from front-end architecture through delivery.
    • Developed the admin panel and the client-facing front-end for a business SMS messaging product.
    • Integrated front-end features with Node.js, Express and .NET back ends, and took requirements and demos directly with client stakeholders.

  3. Oct 2022 – Nov 2023

    Front-End Developer

    NumFin Global

    Full-timeRemote

    • Built and optimized React, Next.js and TypeScript applications for a financial analytics product, with Redux and MobX holding application state.
    • Dashboards and interactive charts over 60,000+ stocks from 70 exchanges. Shipped the payment system and the advertising integrations on the same product.
    • Worked on SEO and Core Web Vitals across the Next.js application, on rendering, metadata and page speed.

  4. Jun 2022 – Oct 2022

    Front-End Developer

    Self-employed

    FreelanceRemote

    • Delivered web projects end to end, from Figma layouts to deployed responsive sites, with React, TypeScript, SCSS and BEM. Completed an intensive front-end program in five months instead of the standard nine.

Before front-end: 2016 to 2022

  • Jun 2021 – Jun 2022

    Python Developer

    Self-employed · Remote

    • Built e-commerce functionality with Python and Django, and containerized a Django REST API with Docker.

  • 2016 – 2022

    Petroleum Engineer

    Oil and gas companies · Russia

    • Delivered the full design, construction and operation cycle for fuel depot sites, coordinating contractors, budgets and regulatory approvals.

Education

2016 – 2019

Tyumen State Oil and Gas University

Master's in Engineering, Oil and gas industry · Tyumen, Russia

2012 – 2016

National Mineral Resources University

Bachelor's in Engineering, Oil and gas industry · Saint Petersburg, Russia

Languages

  • English Professional working
  • Russian Native
  • Portuguese A2, learning

Let's talk

Hiring, a contract, or a second opinion on a front-end that has got away from you.

Messages go through Formspree. I use them only to reply.