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. Tony's Chocolonely
    Tony's Chocolonely

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:

  • leading the headless replatforming of a much loved chain of restaurants, modernising its UK & Ireland web estate;
  • helping prospective car buyers find just the right configuration for their next sports car;
  • helping a major browser vendor explore AI‑driven tools for clearer, more useful browsing experiences;
  • ... 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

    HSBC Corporate
    Banking

    Lead UI development for a set of HSBC digital transformation projects, including a React, TypeScript, Node.js, and AEM rebuild of commercial banking applications.

    Screenshot of the HSBC Corporate Banking website; part of John Kavanagh's selected project work.
  2. Featured case study

    The World Economic
    Forum

    Senior JavaScript developer heavily involved in delivering a React‑based 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.
  3. 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.

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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