Featured case study
Selfridges
Lead front‑end developer within Selfridges' e‑commerce Customer Experience team, delivering new features, considerable refactoring, and platform performance improvements.
Technical Lead & Senior Software Engineer
I'm an independent software engineer and technical lead based in Brighton. I build and improve React, Next.js and TypeScript applications for businesses across the UK, from hands‑on development to complex digital transformations.
I'm John Kavanagh, an award‑winning software engineering specialist based in sunny overcast Brighton, UK.
I am an enthusiastic senior software engineer and technical leader with 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.
I also founded Kavanagh Digital, where I lead independent programme assurance, recovery, and web‑platform due diligence.
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;
- leading a team of developers for the world's local bank, rebuilding their commercial banking platform;
- helping develop the online identity of Volvo's emerging premium EV brand;
- ... and creating a digital home and web shop for a fledgling Sussex vineyard.
Featured Case Studies
- Featured case study
Virgin Atlantic
& HolidaysLead engineer on Virgin Atlantic & Holidays' large‑scale replatforming programme, unifying twelve disparate applications within a new headless architecture built with React and Next.js.
- Featured case study
HSBC Corporate
BankingLead UI development across several HSBC digital transformation projects, spanning commercial banking, React platform development, legacy integration, and complex global banking workflows.
How I Usually Help
Next.js Website and Application Development
Hands‑on Next.js development for new websites, applications, and headless front ends, with accessibility, performance, and publishing workflows included in the build.
Embedded Technical Leadership
Principal‑level support inside active delivery when architecture, standards, mentoring, documentation, ownership transfer, and implementation decisions need strengthening whilst the team keeps shipping.
Next.js Platform Architecture
Define Next.js platform boundaries when domains, routes, tenants, brands, content ownership, data ownership, deployment models, or team responsibilities are making change unsafe.
Headless Architecture Consulting
Headless architecture advice before CMS, content model, preview, revalidation, metadata, schema, media, localisation, and editorial ownership decisions become expensive to reverse.
Next.js Platform Consulting
A platform assessment with a dependency map, a record of the decisions to make, and a prioritised delivery plan for your existing React or Next.js estate.
Performance Optimisation and Core Web Vitals
Route‑level performance work for modern front ends where field data, Core Web Vitals, scripts, fonts, images, data loading, or templates are weakening important user journeys.
Previous Clients
John Lewis logo 
The BBC logo 
GOV.UK logo 
HSBC logo 
British Airways logo 
eBay logo 
Condé Nast Britain logo 
Nintendo logo 
Lotus Cars logo 
Team GB logo 
Marvel Comics logo 
London Philharmonic Orchestra logo 
Bosch (BSH Group) logo 
Volkswagen logo 
Cisco logo 
Activision logo 
London 2012 Olympics and Paralympics logo 
Microsoft logo 
Apple logo 
Gatsby logo 
Plex TV logo 
LEGO logo 
Selfridges logo 
The World Economic Forum logo 
Made by Many logo 
AND Digital logo 
IMG Licensing logo 
Disney logo 
Boohoo Group logo 
Debenhams.com logo 
The Rolling Stones logo 
Wreel Agency logo 
Polestar logo 
MOSCOT logo 
Virgin Atlantic logo 
American Express logo 
The Guide Dogs for the Blind Association logo 
Style.com logo 
Macmillan Education logo 
Zara logo 
Boeing logo 
Valtech logo 
McCann Manchester logo 
Warwick Acoustics logo 
Nando’s logo 
Virgin Active logo
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