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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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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. 📦🐈 Active development trunk for Yarn

    TypeScript 5.6k 865

  2. clipanion Public

    Type-safe CLI library / framework with no runtime dependencies

    TypeScript 770 48

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

    C++ 15.6k 1.3k

  4. typanion Public

    Static and runtime type assertion library with no dependencies

    TypeScript 196 13

  5. High-level DOM-like terminal interface library

    JavaScript 128 15

  6. secretsanta Public

    Host secret santa without leaking your guests' informations 🎄

    HTML 110 72

1,612 contributions in the last year

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

Contribution activity

September 2022

Created 1 repository

Created a pull request in nodejs/node that received 19 comments

module: open stat/readPackage to mutations

While the CJS loader uses the fs module to perform most filesystem I/O, it uses two hidden internal primitives for speed: internalModuleStat, and p…

+37 −7 19 comments

Created an issue in nodejs/single-executable that received 2 comments

Experiment: node-sea

Since the action item of the previous meeting was to build SEA experiments, I built mine: node-sea. It generates JS files that, when required or ex…

Started 1 discussion in 1 repository
Answered 2 discussions in 1 repository
21 contributions in private repositories Sep 2 – Sep 16

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