New job: I am now working at Riverlane

It has been a long time since my last post. Not a year like this last post, but more than 9 months. And a lot happened since then.

My new main activity

As you might have guessed from the title of this blog post, I recently joined Riverlane as a Senior Open-Source Software Engineer to work on Deltakit, a newly open-source library for people interested in quantum error-correction.

One of my first main contribution to deltakit has been an implementation of the error-budgeting work done by the Google team to understand the contribution of each error source to the “error-budget” of their hardware.

I also have done plenty of house-keeping contributions about improving code quality, better compliance with widely used Python tools such as mypy or ruff and add compatibility with new features of external tools (e.g., tag support from Stim). You might also have seen me at the 2025 iteration of the Munich Quantum Software Forum where I presented a pitch and a poster on Deltakit.

Of course, plenty of exciting things are happening internally and I can’t wait to speak about it when it will be made public, so if you are interested in quantum error-correction stay tuned!

What about QraftWare?

I was building my own company, QraftWare, since the beginning of 2023. I learnt a lot in the 2.5 years I spent building it, and one of the core learning I get back from it is that selling stuffs will never be my job. I simply don’t like it, which makes me very bad at it.

With that fact on the table, I found 3 options to go forward:

1. hire someone to do the selling job for me or,
2. associate myself with a co-founder / co-foundress that would have the skills I am missing or,
3. stop my company and find a full-time job.

The first solution, hiring someone, was not possible. I did not have enough money to pay someone.

Options 2 and 3 were both interesting, and both seemed like a good way forward for me. So I investiguated both: looking for jobs on the quantum computing market, while searching for someone with the right skills that I could trust enough to be integrated at a co-founder / co-foundress position.

In the end, option 3 did not work out because I did not know anyone that had the skills I was searching for and that I could trust enough to co-found QraftWare. Also, option 2 turned out to be pretty successfull, with several nice job offers that were all:

• about doing interesting science,
• in companies that I believed in and that are not bullshitting their way through the next venture capital round,
• within the salary boundaries that I thought I could reasonably expect.

So QraftWare is currently being closed (and I am starting to wonder if the paperwork did not end up being lost in the limbo of the French administration).

What about pending projects?

The software I worked on during my time at QraftWare (personal contributions aside, I might make a separate blog post for these) can be split into three categories.

First, the internal software tools I was expecting to sell as a business. These are still closed source, and I am currently weighting the value of making them open-source. If I end up answering yes to that question, I will make a few accompanying blog posts explaining the history of each software, the genesis of the ideas, and the different scientific and technical challenges I encountered and solved in the development process.

Secondly, the public contributions. A large majority of these were made in the TQEC community and led to a successful software library actively used by several research groups in quantum error correction and continuously improved with new ideas arising from various discussions with people from all over the world. For the moment, my active contribution to the project code is on pause, but I plan to get back at contributing as soon as possible!

Thirdly, the personal contributions I made to several projects. For projects related to quantum computing, my contribution is on pause for the moment. For projects unrelated to quantum computing, I am still planning to contribute from time to time, but it is unlikely that these contributions will be public. Nevertheless, I am planning a blog post on one of these project that consisted (and is still ongoing) in resurecting a dead game from my childhood.

What’s next?

I have less time to contribute to this blog, but I still have plenty of things I want to talk about. So expect more posts, probably on quantum error correction or things unrelated to quantum computing, in the next months. Stay updated!