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Writing the open-source software that you may be using everyday
Writing the open-source software that you may be using everyday


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@DataDog @castel @start9 @manaflair @yarnpkg @maintainers

Hi there! 🎉

My name's Maël and I'm a senior software engineer, currently focusing on developer experience (how to improve developer productivity while making our applications more stable?). I jumped into this role back in 2017 when I joined Facebook after years of startups, then kept doing it after moving to Datadog. As part of my role (and also because I like it and I'm lucky enough to have an understanding family 😉), I contribute a lot to the open-source movement.

If you want to support me, feel free to follow me on Twitter (it gives me a wider reach, and thus makes it easier to promote my project updates), or wait until I finally enable this magic Sponsor button. Also feel free to drop me an email!

My work on Yarn

I've been Yarn's BDFL for a few years now (since 2017, approximately). More recently I completely rearchitectured and rewrote the software, which has been a huge undertaking as you can imagine. Fortunately, I've been helped in this endeavor by the arrival of new contributors, finally building the community I dreamt of. Speaking of which, we're always open to new contributors, so ping me on Discord if that might be you!

Finally, I'm also the designer and implementer for Yarn Plug'n'Play (PnP) - so if you see me tell you that you shouldn't rely on hoisting, do me a favour and trust me! After all this time, I feel like I could write a thesis about package management 😄

Other projects

I love to learn by practice, and since I started my journey I touched a bit of everything: full websites, compilers, emulators, terminal interfaces, ... while there's many way to approach software development, I found this one to fit my personality the most. By contrast, I find very hard to follow tutorials or videos when learning new techs!

My two main libraries at this point in time are Clipanion, a CLI framework, and Typanion, a runtime type assertion library. I also have a secret project I hope to show you one day ... one more reason to follow me on Twitter! 💫


  1. 📦🐈 Fast, reliable, and secure dependency management.

    JavaScript 38.8k 2.6k

  2. Yoga is a cross-platform layout engine which implements Flexbox. Follow for updates.

    C++ 13.4k 1.1k

  3. Type-safe CLI library with no dependencies

    TypeScript 209 16

  4. Static and runtime type assertion library with no dependencies

    TypeScript 25 2

  5. JS collection of standardized devices, useful for emulating engines

    JavaScript 213 17

  6. High-level DOM-like terminal interface library

    JavaScript 108 13

2,873 contributions in the last year

Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Mon Wed Fri

Contribution activity

August 2020

Created a pull request in gatsbyjs/gatsby that received 6 comments

Adds back peer dependency

Description The peer dependency got removed in, but it's not clear why since it's still a manda…

+3 −0 6 comments

Created an issue in arcanis/pmm that received 1 comment

Init workflow

This thread is meant to discuss the init workflow. For example, what happens when running yarn init or npm init? Under the current model those comm…

1 comment
33 contributions in private repositories Aug 3 – Aug 7

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