mcat.one

Mateusz Kania

Senior FrontendDeveloper

I build large media sites that tens of millions of people use. Right now that means BBC Good Food, Radio Times and Olive Magazine at Immediate Media.

  • Over ten years
  • Media and fintech
  • Poland, remote

Open to opportunities

Ten years in, the work has settled into one thing: shared platforms at scale. One codebase serving a publisher's whole brand portfolio, where every change ships to every site. React and Next.js on top, the Node.js layer behind them.

Outside the day job I build AI agents. AI_devs 3 Agents in 2024, 10xDevs in 2025, AI_devs 4 Builders in 2026. AI tools are now part of how I write code every day, and that changed how I work more than any framework has.

Experience

2024 now

Senior Frontend Developer

Immediate Media, via emagine

Warsaw, PL · remote

A large, complex codebase shared by every Immediate site, so each change ships to all of them. Much of it is shared functionality: news and page management, the page builder and advertising.

BBC Good Food, Radio Times, Olive Magazine

  • Built US localisation for BBC Good Food: US recipes and measurements behind a Metric/US toggle, served from the Search API.
  • Led the move of our Node.js backend-for-frontend from JavaScript to TypeScript.
  • Added OpenWeb comments and ratings, video players and reCAPTCHA Enterprise.
  • Wrote the product documentation for the localisation work, and review code across the frontend, BFF and component library.
  • Rotate as Release Guardian, looking after the CI/CD pipelines and production deployments.

Burda Media Polska

  • Moved Polki.pl, party.pl, wizaz.pl, Elle.pl, viva.pl and other Polish lifestyle sites onto one Next.js stack.
  • Built the React and Next.js components the new stack was missing, tuned them for Core Web Vitals and covered them with Jest and Cypress tests.
  • Kept the legacy sites running until each one was migrated, and set up the AWS CI/CD pipelines.

2021 2024

Frontend Developer

Statik Space, now Sitebox

London, UK · remote

  • Built a SaaS app for managing WordPress instances in Next.js, React and TypeScript.
  • Wrote the Node.js and GraphQL services behind it, with MongoDB for storage.
  • Made custom Gutenberg blocks in React, and tested the app with Jest and Puppeteer.
  • Animated marketing sites with GSAP and Framer Motion.

2016 2021

Frontend Developer and Team Leader

Nurture Agency, now Gravity Global

Nowy Sącz, PL

  • Led a team of eleven engineers building website components and blocks.
  • Hired and onboarded developers, and planned growth paths for juniors.
  • Was the technical voice in client meetings.
  • Set the team's styling and scripting standards, wrote documentation and reviewed code.
  • Built blocks for Pagebox, our in-house page builder, in React and TypeScript.

Clients: Generali Investments, Hermes, Nordea, OMGI (Merian), Jupiter, CBRE, Sands Capital Ventures, Heptagon Capital, Recognise Bank, Planday, Redstor.

2016

Graphic Designer

Vantis Holding

Nowy Sącz, PL

  • Designed landing pages, edited video and made ads and social media graphics.

Stack

Languages

  • TypeScript
  • JavaScript (ES6+)

Frameworks

  • React
  • Next.js
  • Gatsby
  • Redux
  • MobX

Styling and motion

  • GSAP
  • Styled Components
  • Tailwind CSS
  • Material UI
  • Ant Design
  • Web Components
  • Storybook

Testing

  • Jest
  • Cypress
  • Puppeteer

Backend and data

  • Node.js
  • Express
  • GraphQL
  • REST
  • MongoDB
  • MySQL
  • MariaDB

AI

  • Claude Code
  • OpenAI API
  • Langfuse
  • Promptfoo
  • Pinecone
  • Neo4j

Platform

  • AWS
  • Docker
  • CI/CD
  • Git
  • Webpack
  • Auth0
  • Gutenberg
  • Figma
  • Jira
  • Scrum

Let us talk

Hiring, contracting, or just want to compare notes on making big sites fast.

LinkedIn is the fastest way to reach me.