Principal Software Engineer & Technical Lead

Handson engineering leadership for complex digital transformation programmes. I help product and engineering teams turn fragile legacy web estates into robust platforms that are faster and easier to maintain, scale, govern, and improve.

I'm John, an awardwinning software engineering specialist based in sunny cloudy Brighton, UK.

I am an enthusiastic principal software engineer and technical leader with over twentythree years of handson experience.

I help teams and clients design, build and improve websites, applications and web platforms, pairing architecture, delivery judgement and handson TypeScript, React, HTML, and CSS.

My portfolio is diverse; I work with global clients, solving real-world problems, including:

  • helping a major browser vendor explore AIdriven tools for clearer, more useful browsing experiences;
  • helping prospective car buyers find just the right configuration for their next sports car;
  • engaging businesses, politicians, academics, and world leaders to shape global agendas;
  • ... and revamping the online presence of a local food truck so that their customers knew where to find them.
More about me

Featured Case Studies

  1. Featured case study

    Virgin Atlantic
    & Holidays

    Lead engineer on Virgin Atlantic & Holidays' largescale replatforming programme, unifying twelve disparate applications within a new headless architecture built with React and Next.js.

    Screenshot of the Virgin Atlantic & Holidays website; part of John Kavanagh's selected project work.
  2. Featured case study

    The World Economic
    Forum

    Senior JavaScript developer delivering a Reactbased rebuild of the World Economic Forum's online platforms, whilst also leading the introduction of new user features.

    Screenshot of The World Economic Forum website; part of John Kavanagh's selected project work.
  3. Featured case study

    Polestar

    Senior developer on Polestar's highly animated, interactive website and automotive configurators, built with Gatsby, React, and TypeScript as Volvo's former gofaster brand evolved into an EV company.

    Screenshot of the Polestar website; part of John Kavanagh's selected project work.
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Previous Clients

Availability

I am currently leading a global digital transformation engagement, with limited availability until late 2026. Short diagnostics or urgent work may be possible sooner.

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Looking for technical direction?

I support teams that need senior judgement on React, Next.js, headless CMS architecture, performance, migrations, and technical SEO.