Senior Software Engineer & Technical Lead

Hands‑on technical leadership for digital transformation programmes, specialising in complex Next.js and React replatforming, migrations, platform architecture, performance, and technical SEO.

  1. Nando’s
    Nando’s

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

I am a friendly and enthusiastic senior 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 modernisation of the online portfolio of one of Britain's largest airlines;
  • 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;
  • ... 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

    LEGO

    Senior developer producing an all‑new e‑commerce platform with React. Designed to handle high traffic volumes and support multi‑language and multiple currencies.

    Screenshot of the LEGO website; part of John Kavanagh's selected project work.
  2. 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.
  3. 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.

How I Usually Help

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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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Latest Articles

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  1. SEO Best Practices in Next.js: Improving Core Web Vitals.
    Read article
    SEO Best Practices in Next.js: Improving Core Web Vitals.

    SEO Best Practices in Next.js: Improving Core Web Vitals

    SEO best practices in Next.js, with a sharper focus on Core Web Vitals, stable layouts, lighter bundles, metadata, and real user measurement for search.

  2. Google's Search Monopoly Was Built on a Deal. AI is Rewriting It.
    Read article
    Google's Search Monopoly Was Built on a Deal. AI is Rewriting It.

    Google's Search Monopoly Was Built on a Deal. AI is Rewriting It

    Google's old exchange was simple: crawl the web and send traffic back. AI search weakens that bargain by answering more journeys before the click.

  3. Why Your Next.js App Router Page is Stale: Cache Tags, Revalidation, and CMS Publishing.
    Read article
    Why Your Next.js App Router Page is Stale: Cache Tags, Revalidation, and CMS Publishing.

    Why Your Next.js App Router Page is Stale: Cache Tags, Revalidation, and CMS Publishing

    Debug stale Next.js App Router pages with cache tags, revalidation paths, CMS webhooks, preview freshness, dependency graphs, and simpler cache contracts.

  4. Contentful to Sanity Migration Risks for Next.js Sites.
    Read article
    Contentful to Sanity Migration Risks for Next.js Sites.

    Contentful to Sanity Migration Risks for Next.js Sites

    Contentful to Sanity migration risks for Next.js sites, including models, references, rich text, preview, metadata, redirects, and launch checks.

  5. AI and the Collapse of Organisational Memory.
    Read article
    AI and the Collapse of Organisational Memory.

    AI and the Collapse of Organisational Memory

    AI knowledge retrieval can weaken organisational memory when summaries hide context, dissent, incident history, product reasoning, and uncertainty.

Want to find out more?

If you need senior hands‑on 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.

Get in touch