Hi, I’m Andy Jessop. I’m a staff engineer with over 16 years of experience building maintainable, accessible, testable, and performant software, and these days I work at Cense, solving complex problems and driving innovation across the org.

The one-line version of my career reads: freelance developer, then Chess.com, then Glassnode, then Cloudflare, the Cense. The longer version is more interesting, so here it is properly.

I came to software by way of electronic engineering: a BEng in Electronic Engineering at the University of Leeds, where my dissertation involved implementing a cryptographic algorithm using the Fast Fourier Transform, followed by an MSc in Nanoscale Science and Technology at Sheffield/Leeds. In 2009 I started freelancing, designing, building, and maintaining websites and internal tools for clients across product engineering, infrastructure, tooling, and design systems. The most memorable project was a modern intranet for Mercedes-Benz South-West UK. Six years of client work teaches you to ship: real deadlines, real users, and nobody to hide behind.

In 2015 I joined Chess.com as a Front-end Developer and stayed for over six years, which in internet time is a couple of geological eras. I worked on the architectural and performance transition from v2 to v3 of the platform, and led a small team building a modular chessboard framework that supported billions of games played across the site. When code you wrote gets exercised at that scale, you learn very quickly what performance and maintainability actually mean.

From there I moved to Glassnode as Senior Front-end Developer and eventually Tech Lead. I led the Query Platform project, a strategic initiative supporting the company’s transition from B2C to B2B. Day to day that meant modernising the front-end architecture, testing, build tooling, and monorepo workflows: reduced CI times, faster deployments, and meaningful performance improvements across the product. This is where I found out I genuinely enjoy the unglamorous side of engineering. A faster pipeline changes how a whole team behaves.

That taste for developer experience took me to Cloudflare as a Senior Systems Engineer, working on developer experience and observability with a focus on building reliable, scalable software. Making life easier for other engineers turned out to be the job description I’d been writing for myself all along. It’s also where I got to work seriously with AI: I built a repository of Workers AI examples and a style guide for building AI applications on Cloudflare Workers.

Outside the day job I build in the open, and lately almost everything has been agentic AI or developer tooling. The current obsessions:

  • synapse, a bare-bones event-driven agentic framework: local-first, scenario-driven, with events and agent runs in Postgres and traces in Jaeger
  • pi, an AI-first JS architecture built on a simple bet: if routes are plain data, components are pure, and side effects live in lifecycle-aware middleware, then AI systems can understand, generate, test, and debug their own code
  • ts-facts, a small CLI that walks a TypeScript program with the compiler API and writes a single JSON file of static facts, for tooling and analysis
  • ers, a package-composed agent platform

Further back, some projects I’m still fond of: bakery, a Bun-based monorepo task runner built for ludicrously good DX and lightning-fast CI. pivot, a front-end state management framework for highly decoupled, long-lived code. cachier, a Cloudflare Worker-based remote cache for Nx monorepos. monorepo-starter-kit, still the most-starred repository on my GitHub. And crux with redux-dynamic-registry, from a long-running interest in keeping browser code decoupled and lightweight.

How I think about software

I love experimenting, building, and learning through fast iteration. Most of my side projects started as a question that wouldn’t leave me alone.

I care deeply about quality and longevity. I prefer simple, durable systems built on strong foundations: use the platform, reduce unnecessary complexity, and make the right thing easy.

What I’m interested in

  • Building useful products and tools
  • Fast iteration and experimentation
  • Developer experience and productivity
  • Web performance and accessibility
  • AI-assisted workflows
  • Infrastructure, platforms, and automation
  • Long-lasting, maintainable software

Get in touch

I’m always happy to talk about engineering, tooling, infrastructure, AI, product ideas, or anything experimental. You can find me on GitHub, or reach me by email.