Senior Software Engineer & Technical Lead

Hands‑on technical leadership across complex Next.js and React platforms, digital transformations, technical SEO, performance, migrations and platform architecture.

  1. The World Economic Forum
    The World Economic Forum

I'm John, an award‑winning software engineering specialist based in sunny overcast 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:

  • engaging businesses, politicians, academics, and world leaders to shape global agendas;
  • helping a major browser vendor explore AI‑driven tools for clearer, more useful browsing experiences;
  • leading the headless replatforming of a much loved chain of restaurants, modernising its UK & Ireland web estate;
  • ... 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

    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.
  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

    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.

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. State Management in Angular: NgRx vs. SignalStore.
    Read article
    State Management in Angular: NgRx vs. SignalStore.

    State Management in Angular: NgRx vs. SignalStore

    NgRx Store vs. SignalStore explained with real Angular trade‑offs, including scope, TypeScript ergonomics, devtools, effects, and when neither is necessary.

  2. AI is Making Technical Debt Cheaper to Create.
    Read article
    AI is Making Technical Debt Cheaper to Create.

    AI is Making Technical Debt Cheaper to Create

    AI coding tools make code faster to produce, but technical debt still needs review, ownership, tests, documentation, and senior engineering judgement.

  3. Traffic Dropped After a Replatform: The Technical Checks I Run First.
    Read article
    Traffic Dropped After a Replatform: The Technical Checks I Run First.

    Traffic Dropped After a Replatform: The Technical Checks I Run First

    Diagnose traffic drops after a redesign, migration, or replatform by checking route parity, rendered HTML, redirects, canonicals, sitemaps, and schema.

Need a senior engineer involved?

I can work directly in the codebase, review the architecture, or support the team through delivery when the work needs more than extra hands.

Get in touch