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 faster, more maintainable platforms that are easier to scale, govern, and improve.

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

I am a friendly and enthusiastic principal software engineer and technical leader backed by 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 prospective car buyers find just the right configuration for their next sports car;
  • overseeing the digital rebranding of a chain of muchloved highend department stores;
  • engaging businesses, politicians, academics, and world leaders to shape global agendas;
  • ... and enhancing the website of a local toyshop so that they could continue trading during lockdown.
More about me

Featured Case Studies

  1. Featured case study

    The World Economic
    Forum

    Senior JavaScript developer heavily involved in delivering a Reactbased rebuild of the World Economic Forum online platforms, including leading the introduction of new user features.

    Screenshot of The World Economic Forum website; part of John Kavanagh's selected project work.
  2. 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.
  3. Featured case study

    Polestar

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

    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 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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Want to find out more?

If you need senior handson support with a complex React or Next.js platform, migration, performance issue, or technical SEO problem, send me the context and I'll tell you where I can help.