Principal Software Engineer & Technical Lead

Hands‑on engineering leadership for complex digital transformation programmes. I help product and engineering teams turn fragile legacy web estates into faster, more maintainable platforms that are easier to scale, govern, and improve.

  1. MOSCOT Eyewear
    MOSCOT Eyewear

I'm John, an award‑winning software engineering specialist based in sunny Brighton, UK.

I am a friendly and enthusiastic principal software engineer and technical leader backed by over twenty‑three years of hands‑on experience.

I help teams and clients design, build and improve websites, applications and web platforms, pairing architecture, delivery judgement and hands‑on 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 AI‑driven tools for clearer, more useful browsing experiences;
  • engaging businesses, politicians, academics, and world leaders to shape global agendas;
  • overseeing the digital rebranding of a chain of much‑loved high‑end department stores;
  • ... 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 this massive replatforming project, unifying twelve disparate applications under a new headless architecture with React and Next.js.

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

    Polestar

    Senior developer working on this highly animated, interactive website and automotive configurators for Polestar, once Volvo's fledgling go‑faster brand, now turned EV company. Built with Gatsby, React, and TypeScript.

    Screenshot of the Polestar website; part of John Kavanagh's selected project work.
  3. Featured case study

    John Lewis
    & Partners

    Senior developer as part of team 'Findability'. Led the digital implementation of the 'John Lewis & Partners' rebrand alongside new feature development, user journey optimisation, and performance improvements.

    Screenshot of the John Lewis website; part of John Kavanagh's selected project work.

How I Usually Help

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Availability

I am currently leading a new digital transformation engagement, with availability for selected consulting and engineering delivery from September 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.

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