So you know ls (often found as /bin/ls), the good old Unix command to list files in a directory.

I recently came across exa, a modern replacement for ls. It is part of a wave of new command-line tools written in Rust and that bring modernity while staying faithful to the Unix way of writing focused and composable tools.

Of course you may wonder why switching from ls is any good idea. …


  • an academic sabbatical, and
  • a career bet, and
  • a job change, and
  • a minor health issue and my ever first surgery, and
  • a pandemic that greatly disrupts lives across the world…

I am happy to announce that my book Vert.x in Action (Asynchronous and Reactive Java) has been published! 🥳

I have so many people to thank that the best is to read the acknowledgements section of the book 😇

Writing this book has been a long and fun journey. I wrote this book with the goal of teaching concepts that will still be relevant in the years to come, and I hope that you will learn useful lessons from it!

Have fun and take care 👍

🚀 Get Vert.x in Action book from Manning

Originally published at on October 29, 2020.

I spend a fair amount of time in terminal emulators, and here is how I get a good experience on macOS. I use iTerm2, Zsh, and a few cool command-line tools.


I am working on macOS, and I prefer the iTerm2 terminal emulator over the macOS Terminal application:

I especially enjoy the ability to split panes horizontally and vertically, as well as the keyboard shortcuts to move around.

I use the minimal theme with the tab bar on top and the status bar in the bottom with a few helper icons like CPU usage and current process. The color theme…

Photo by Daniele Fantin on Unsplash

It seems like the whole Java ecosystem is going mad these days with GraalVM. Every library and framework wants to proudly work on GraalVM, making GraalVM a new silver bullet for modern Java applications.

I expect the GraalVM crazyness to follow the typical hype cycle, and soon we will hear of disillusions and people will actually understand what GraalVM is — and more importantly — what GraalVM is not.

Where does Graal(VM) comes from?

Graal is a what happens when you give a group of academic and industry researchers ample time and budget to work on interesting problems.

The history of Graal dates back to…

This post was originally published on Red Hat Developers, the community to learn, code, and share faster. To read the original post, click here.

I had the pleasure to present “Eclipse Vert.x for Dj fun and for profit!” at the latest edition of the Jug Summer Camp in La Rochelle, France.

The Jug Summer Camp is a popular developer conference organized by Serli in western France, gathering regional attendees as well as speakers and participants from other French Java user groups.

My talk was an introduction to reactive programming with Eclipse Vert.x, featuring demos with RxJava-based edge services as well…

Dear JetBrains, Dear Kotlin community,

I recently played with Kotlin, first with the interesting RxJava 2 library. I quickly stumbled upon lots of surprising pitfalls in passing lambda expressions.

It turns out that unless you had properly read the language reference guide and remember to use the Groovy-style way of passing lambdas, IntelliJ quickly pushes you in the wrong direction and you end up with monster code.

I recorded a quick example with Java streams:

All I did was typing using smart completion and quick fixes and I ended up with a strange code that seemed to compile but failed with a typecast at runtime.

I hope that the smart folks at JetBrains will use this as a useful feedback for improving the IDE experience.

Have fun!

I am not a big fan of HTML slides. For sure many fancy tools and libraries exist in that space, but no matter what I always prefer the pixel-perfection of a tool like Apple Keynote. Pushing pixels is what I prefer doing for public talks and important meetings.

The flip side of the coin is that crafting great slide decks is time consuming. There is a context where having just good enough slides is key: teaching.

Teaching slide decks are always big, and you need to put lots of text for students. Doing a public talk with lots of text…

I am very happy to announce that I am joining the Vert.x team at Red Hat starting next Monday!

I will work part-time as a delegated consultant to Red Hat thanks to an agreement with INSA-Lyon where I will continue my academic projects and duties.

After a few years in Academia I felt the need to get some fresh “hands-on” industry experience and step out of my comfort zone. Eclipse Vert.x is a vibrant project that matches lots of my and my Dynamid research team current interests. …


It’s 2016 and you can’t ignore that all trendy hipster developers do reactive applications.

If you aren’t doing reactive programming these days, then you are so old-school and your applications just cannot scale. And of course we all know that you need to cope with millions of network requests per-second, right?

Sadly most of us developers have missed the most popular reactive application development platform. Worse: it’s been around for decades.

It’s called Excel

Excel is the #1 application development platform

It’s everywhere (“shadow IT”), and it’s been used by non-developers to build “Frankenstein Tools” (c) (r) (tm).

Every time there’s a need, then there’s a spreadsheet…

Unboxing a new machine is fun, provisioning it is not always so fun.

I’ve decided to invest a bit of time to prepare myself a Git repository of dotfiles and configuration scripts. These scripts do 80% of the work to get me started on a new machine. My focus has been to make something deliberately simple, and you can check it out on GitHub:


Julien Ponge

Computer scientist. Hackademic. Does more with less.

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