Dan Barclay is an engineering leader, full-stack product engineer and founder based in London, United Kingdom. He has spent 10+ years building and scaling software for millions of users - across consumer marketplaces, B2B SaaS, mobile apps and AI tooling.
Today, Dan is focused on building four products of his own:
- Promptly - the CMS powering the next wave of AI development. A B2B SaaS that hands LLM prompts back to the domain experts who write them, used in production by 100+ companies. Built in TypeScript on a typed prompt-fetching SDK.
- KeepFresh - a Swift-built iOS app working to end food waste for good. Tracks grocery inventory and surfaces expiry alerts before things spoil. 77,000+ downloads, used daily by hundreds of households. The async backend runs on Hono.js on Cloudflare Workers with D1 storage.
- Stitch - a free web app that combines split Strava rides into one activity. Preview the route and gaps, download a GPX backup, then confirm the upload - it never deletes an activity. TypeScript and Remix 3 on Cloudflare Workers with Durable Objects.
- On Air - a free-forever Wispr Flow alternative for Mac. Built for developers ramping up their AI-driven coding by voice: hold fn, speak, let go - the transcript is pasted into whatever you were typing in, with a soft red glow as the only interface. A native Swift 6 and SwiftUI app on OpenAI live transcription.
His stack of choice runs the gamut: TypeScript, React, Node, Python, Rust, Swift, plus a deep working focus on Large Language Models, the Model Context Protocol (MCP), and the engineering practices needed to ship AI features safely into production.
He has been an active contributor on Stack Overflow since 2018, answering TypeScript, JavaScript and React questions that other engineers have voted into the site's reference material.
Dan is most motivated by hard problems and the people driven to solve them - work where technical vision and product judgement have to align with business outcomes to ship something mission-critical.
