jd:/dev/blog_
Julien Danjou

Julien Danjou

24 years building open-source software, writing about it, and occasionally convincing other people to do the same.

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CEO of Mergify, helping engineering teams ship faster. Investing in early-stage SaaS startups as a business angel. Running the Toulouse SaaS Club, a non-profit for local SaaS founders. Based in Toulouse, France.

2002 Debian

Debian developer

Became a Debian developer at 18. Already arguing about package dependencies.

2003

Started blogging

Opened a blog. Apparently couldn't stop. Still at it 23 years later.

2006

Moved to Paris

Moved to Paris. The city where every tech meetup ends at a bar.

2006 Easter-eggs

Easter-eggs

First real job: sysadmin at Easter-eggs, a cooperative dedicated to open-source projects. Got bored pretty fast, so I started writing C and Python on the side and packaging stuff for Debian. Classic.

2007 awesome wm

awesome window manager

Created awesome, a tiling window manager for X. Named it with zero irony. If you've used Linux, you might have heard of it.

2008 Freedesktop

Freedesktop, XCB & X11

Contributed to Freedesktop, XCB and X11. Because apparently building a window manager wasn't enough pain.

2010 GNU Emacs

GNU Emacs & Lisp

Started contributing to GNU Emacs. Got deep into Lisp, ended up maintaining a few Common Lisp packages and wrote a bunch of Emacs extensions published on GNU ELPA — including oauth2 and rainbow-mode. Contributed to Org-mode.

2011 OpenStack

eNovance & OpenStack

Joined eNovance, launching the first European OpenStack cloud. Became one of its most prolific contributors. Created Ceilometer, the telemetry platform, and led it as PTL for several years.

2014 Red HatPython

Red Hat, Gnocchi & a book

Joined Red Hat. Created Gnocchi, the first ultra-scalable time series database. Self-published The Hacker's Guide to Python. Named in Tariq Krim's list of 100 notable French developers, compiled for the French Tech initiative.

2017 Python

Scaling Python

Published book number two: Scaling Python. Because one book about Python wasn't enough.

2019 Python

Serious Python

Published Serious Python with No Starch Press. 25,000+ copies sold. Turns out people want to write better Python. I wrote about a decade of writing books.

Serious Python book cover
2019 Datadog

Datadog

Built a Python profiler from scratch at Datadog. Spent a lot of quality time inside CPython internals.

2019

Mergify

Co-founded Mergify. Helping engineering teams merge code, manage CI/CD, and ship faster.

Mergify logo
2021

Business Angel

Started investing in early-stage tech SaaS startups.

2021

Moved to Toulouse

Left Paris after many years for the south of France.

2023

Nom d'un Pipeline !

Launched the first French podcast on CI/CD. Someone had to.

Julien Danjou recording the Nom d'un Pipeline podcast
2025

Toulouse SaaS Club

Founded the Toulouse SaaS Club, a non-profit bringing local SaaS founders together.

Toulouse SaaS Club logo

Off the clock

Julien Danjou running a half-marathon in Toulouse

When I'm not shipping code or reviewing pull requests, you'll find me obsessing over Neapolitan pizza dough hydration or slow-smoking brisket on a kamado. I run half-marathons — not fast, but I finish. I'm a top 2% FPS player — was Global Elite in CS:GO and Master in Apex Legends. Competitive gaming is basically debugging under pressure with worse teammates.