Jezen Thomas

Jezen Thomas

I'm a programmer and entrepreneur. Occasionally I write about technology, and speak at conferences. Find me on Instagram, or on GitHub, or write me an email.


Cofounder & CTO @ Riskbook, a trading platform for the reinsurance industry. We're revolutionising the way reinsurance underwriters and brokers trade risk programmes. I run this company together with two industry experts, and an excellent team of programmers.


I am the founder of a SaaS business called NewBusinessMonitor. It is a tool primarily for B2B marketing in the UK. If you have a business and you want to sell your goods and/or services to any of the 12,000 new companies registered in the UK every week, you should sign up.


Comparestack is a price comparison technology platform I co-founded together with a business partner. Our platform and provider partnerships make it easy for clients to instantly unlock new revenue streams.

Technical Writing

Occasionally I write technical articles, and some of them have made other programmers mad enjoyed time on the front page of Hacker News. Some of the more popular articles include How I Write Invoices in Vim, Showing The Weather In Tmux, and Using Git To Manage TODOs. If you like, you can view all posts.


Haskell on Rails at Falsy Values conference, Warsaw

Haskell on Rails

Build Stuff — Odessa, Ukraine

July 12, 2016

For years, Rails has been the framework of choice for developers who need to Get Things Done. But what happens when the complexity of the system inevitably grows? We write tests, and more tests, and even more tests, and still we're on our knees, fighting fires and debugging. We need better tools. In this talk I show how build web applications with one of the fastest and most stable languages in the industry: Haskell.

Watch talk on YouTube →

The World's Most Boring Build System at Falsy Values conference, Warsaw

The World's Most Boring Build System

Falsy Values — Warsaw, Poland

October 12, 2015

The front-end community has matured immensely in the past five years with automated build systems and package managers written in JavaScript becoming commonplace. But how did we get here? And what has this really cost us? We know every line of code is a liability, and the best line of code is the one that doesn’t exist. JavaScript build systems are complicated and verbose, and it doesn’t need to be this way.

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Repository Statistics with Git and D3 at Falsy Values conference, Warsaw

Repository Statistics with Git and D3

Falsy Values — Warsaw, Poland

October 12, 2015

A short talk on extracting repository statistics with Git and Bash, and visualising the data in a line graph generated with the D3.js JavaScript library. This is useful for developing an understanding of how your software project is growing and (hopefully!) shrinking over time.

Watch talk on YouTube →

Interview on the Developer on Fire Podcast

Simplicity Master

Developer on Fire Podcast

December 31, 2015

An interview for the Developer on Fire podcast where I chat with Dave Rael about great tools, mastering the command line, the primacy of simplicity, and geeking out about the rotation axes of the arms when typing. Includes rants about JavaScript, stories of failure, and advice for broadening your skills as a developer.

Listen to the interview →