Senior Software Engineer · Swansea, Wales
Founder, lead engineer, full-stack. Fourteen years across mobile, web, API and data. Delivered end to end.
I am Rhys Williams, a full-stack engineer based in Swansea. I have spent fourteen years building software, the first decade in .NET and Java, the last few in TypeScript and React. The throughline is judgement at speed: real systems with real constraints (multi-tenancy, regulated data, geospatial scale), delivered solo or in small teams, and taken all the way to people using them.
Selected work
Lead engineer, contract · Jun 2025 – Jul 2026
Enterprise property-data platform: 7.4M leases matched to owners and served as a national map.
Founding engineer · Jun 2025 – present
Founding engineer on a live UK waste-carrier marketplace and fleet ops app: iOS, Android and web.
Solo engineer · Jun 2025 – present
A finance app I built to run my own limited company: tax estimates, invoicing and AI-assisted bookkeeping.
Solo engineer · Feb 2026 – present
A procurement-intelligence SaaS that turns scattered UK tender data into one searchable bidding workflow.
How I work
I take an idea to production across mobile, web, API and data, solo or in a small team, and stay responsible for it once people are using it.
I write the spec, direct AI coding agents from it, and own the architecture, the review and the correctness of every commit. AI is a tool I direct, not one I defer to.
Multi-tenancy, regulated data, payments, geospatial scale. The interesting part is the constraint, and getting it right under one.
If you are hiring for someone who can take an idea to production without much hand-holding, have a look at the work, then get in touch.