CAVEHILLlab
Product engineer · Belfast
I'm Darren McSorley, a product engineer with 17 years' experience building web and mobile software — from early product thinking through to reliable production systems.
Product engineer for the ambiguous bit.
I'm most useful before the spec exists: working out with people what they actually need, then building it properly.
For the last four years I ran my own studio, Default Development, which meant owning the parts most engineering roles don't — scoping, commercial terms and supporting what ships in production. Cavehill Lab is where I'm taking that work next.
- 01
Start with the problem
We agree what success looks like before anyone writes code. Scoping is where expensive mistakes are cheapest to fix.
- 02
Ship early, in small pieces
Working software in front of real users quickly, then improve it based on what they actually do.
- 03
Own it in production
Monitoring, fixes and clear handover are part of the job, not an afterthought.
A broad toolkit, used pragmatically.
Highlighted is what I reach for day to day. The rest I've worked with on real projects and can pick back up quickly.
React · Next.js · TypeScript · Tailwind CSS · Vue · Storybook · Progressive Web Apps · Phaser · Three.js · Playwright · Vitest
React Native · Expo · EAS Build · App Store and Google Play release management
Node.js · NestJS · PostgreSQL · REST API design · GraphQL · Laravel / PHP · Ruby on Rails · MySQL · Firebase · Supabase
AWS · Docker · CI/CD · Cloudflare · Azure · Google Cloud · Kubernetes · DNS & email deliverability
LLM API integration · RAG pipelines · Agent orchestration · MCP tooling · LangChain / LangGraph / LangSmith · Streaming interfaces · Prompt design · Evaluation and cost control
Discovery and scoping · Technical pre-sales · Commercial contract design · Team leadership · Accessibility · Cyber Essentials certified
Let's make something useful.
Have a product idea, a technical problem, or a role that sounds interesting? Send a note — I usually reply within two working days.