Warsaw, Poland · works with teams worldwide

Filip Sobczak

Lead Front-end Engineer — React · TypeScript · AI-assisted

Seventeen years of front-end engineering for London's startups, banks and household names — ITV, Wayfair, Trainline, Deutsche Bank, Busuu — the last seven of them consulting with Equal Experts, currently for a global payments platform. Deep in React: architecture, performance, design systems. I lead teams and use agentic AI workflows to move faster than a traditional one.

Get in touch See my work

17+ years shipping the web

2008 →writing production code

Reacta decade deep

Team leadmentoring & code review

AI-nativeagentic workflows daily

about

The short story

I've spent over a decade in London shipping front-ends for startups, banks and household names — Busuu, Trainline, Deutsche Bank, IHS Markit, ITV, Wayfair among them. For the last seven years and counting I've been a consultant with Equal Experts, joining client teams to build products and raise their engineering bar. Before London I founded a startup in Cracow building campaign apps for brands like IKEA and HP; along the way I led front-end teams, mentored engineers, and gave the odd conference talk.

React is my home turf: component architecture, rendering performance, state management, design systems. I've shipped it across streaming TV, e-commerce, travel and pharma — and most recently fintech, building and modernizing merchant-facing portal applications for a global payments platform: shared component libraries and migrations that pay off legacy debt without stopping the roadmap.

I care about the unglamorous things that make software good: clear architecture, honest code review, fast feedback loops. And I'm all-in on AI-assisted engineering — agentic tools are part of my daily workflow, and they've changed how much one engineer can ship.

Daily drivers

React TypeScript Claude Code Next.js Node.js Tailwind Vite pnpm monorepos Design systems Storybook CI/CD Vercel Datadog PostHog

what i do

Four things, done well

React product engineering

React, TypeScript, Next.js. From an empty repo to a product people use — component architecture, data fetching, performance, testing, and the whole unglamorous path to production.

Front-end architecture

Design systems, shared component libraries, monorepos, and gradual migrations off legacy stacks — the kind that ship value every sprint, not in a big bang.

Tech leadership

Leading and mentoring small teams, building code-review culture, and keeping agile pragmatic — shipping beats ceremony.

AI-assisted engineering

Agentic coding is my daily workflow, not a demo. I design the process around it — specs, review gates, verification — so you get the speed without the slop.

experience

Highlights

NOW · VIA EQUAL EXPERTS

Global payments platform — Lead Front-end Engineer

Building and modernizing a family of merchant & partner portal apps for a global fintech: a shared component library, app redesigns, and engineering standards (linting, formatting, CI, tooling) rolled out across many repositories.

2019 → · SEVEN YEARS AND COUNTING

Equal Experts, London — Senior Front-end Engineer

Consulting for household names: built a Connected TV React app for ITV from scratch, bulk Google-Ads campaign tooling for Wayfair, the design system behind Awaze's rental portals (Cottages.com, Novasol), and an online-prescription POC for Lloyds Pharmacy.

2013 – 2019

Senior & lead roles across London

Trainline (co-built the open-source AWS Environment Manager), IHS Markit (led a team on stock-data apps), Quidco (lead front-end on a greenfield e-commerce SPA), Deutsche Bank (D3 market visualizations), Root Capital, pebble {code}, and Busuu, where I led the front-end team in the AngularJS days.

2011 – 2013

Founder — Digital Invaders, Cracow

Built a platform for generating social-media marketing apps, and shipped bespoke Facebook campaign apps for HP, IKEA, Norton and Mont Blanc — the whole process, design to deployment.

2005 – 2010