Hacking Borders: Our participation in Hack Days 2025 in Paris

Last month, we wrote a blog post about our participation in Hack Days 2025, a hackathon organized by the digital directorate of the French government, DINUM (direction interministérielle du numérique). In this blog post, we’ll tell you what we did, what we learnt and what all this means for digital sovereignty.

The event

Cette vidéo est disponible en anglais.

Hack Days brought together over 300 talented developers, designers and innovators from 17 countries to collaborate on open source projects, notably DINUM’s own suite of applications for the public sector in France, called LaSuite. The event also aimed at strengthening European digital sovereignty by exploring the potential for cross-border collaboration.

The 53 different teams worked together over the course of three days to design, develop and pitch their projects to juries at the lovely Jourdan campus of the historic École normale supérieur (ENS).

Our own team consisted of Wieland Lindenthal, Dominic Bräunlein, Bruno Pagno, Eric Schubert and Parimal Satyal.

Our pitch

Before we explain the project in more detail below, here’s a clip of our five-minute pitch:

Cette vidéo est disponible en anglais.

In the first round of the hackathon, the teams made a 3-minute pitch privately to the juries for a chance to be selected in the top 10 projects. OpenProject was luckily one of those ten, and we were then invited to make our 5-minute public pitch (above) the next day.

The jury consisted of Stéphanie Schaer, director of DINUM; Markus Richter, State Secretary at the Federal Ministry for Digital and State Modernization in Germany; Boris Van Hoytema, Quartermaster of the Open Source Program Office within the Ministry of the Interior in the Netherlands; Jean-Baptiste Kempf, the founder of VLC; and Valérie Dagand, managing director of Numeum.

We were very happy to be part of the top three winners, coming in second place.

We would like to congratulate all the winners of the hackathon:

• First: Visio Room Connector, which made Meet (LaSuite’s video conferencing tool) compatible with real-world video conference rooms (SIP Video Interoperability).
• Second: Hacking Borders - Integration Docs with OpenProject (that’s us!)
• Third: Math & chart integration into Docs, which made it possible to write and display LaTeX in Docs.
• Public vote: Panographix, which makes it easy for public servants in France to create and share interactive databases and charts directly within Docs using Grist.

Our project

For OpenProject, our goal in the hackathon was to build a deep integration with Docs, a collaborative note-taking app that’s part of DINUM’s LaSuite.

Remarque

Docs also recently joined the openDesk ecosystem initiated by ZenDiS in Germany. OpenDesk brings together powerful open source tools like OpenProject to offer a digital workplace for public institutions. The collaboration between DINUM and ZenDiS around Docs and OpenProject is an example of cross-border cooperation in digital sovereignty.

Docs is built on BlockNote, an open source rich text editor built on the concept of ‘blocks’. A block can be anything from simple text, a heading, a quote, an image or more complex elements like embedded media, file attachments or custom plugins.

We wanted to harness this extensibility to create a two-way integration such that users could seamlessly go from editing a draft text document in Docs to extracting tasks and text to OpenProject, where they can exist and evolve in a project context.

Such an integration made a lot of sense to us to harness what each tool does best. Docs is a powerful medium to jot down ideas and collaborate with other people, but plain text is not actionable. You cannot easily set an assignee, assign dates, track status, add comments, attach files or integrate with GitHub; all that, however, is very simple to do in OpenProject.

Our integration makes it possible to:

• Write a bullet list in plain text and easily turn it into a set of tasks in OpenProject.
• Select text from any part of a document and turn it into a user story or work package in OpenProject. We even implemented a basic LLM layer to convert the text to fit a predefined format.
• Maintain a ‘live’ link between objects: a change in Docs is reflected near-instantly in OpenProject and vice-versa. This makes it possible to avoid content duplication and have a single source of truth.

Enterprise-grade integration

We used open, enterprise-grade standards like OpenID connect to support single sign-on. This is because we believe that ensuring users can be logged in with the same credentials on OpenProject and on Docs is key to making the user experience seamless and increasing user adoption of both tools.

We also wanted to build the integration in as generic a manner as possible. Because Docs is built with BlockNote, we decided to approach the integration as an OpenProject block within the editor itself, which will make it possible for any other application using BlockNote to also integrate with OpenProject. This was important to use because we believe that lowering the cost of integration between open source tools is key to European digital sovereignty.

What we learnt

We were very impressed with the turnout, the excitement around open source, the quality of the teams and the projects and the organization of such an event. Some learnings we came back with:

• Broad interest in sovereign open source software: The event highlighted a significant interest across Europe in developing sovereign open source software. The turnout and enthusiasm were clear indicators that dependence on American big tech is increasingly a concern and that there’s value in working together with other European open source projects.

• Diverse strategies across Europe: We observed that different countries have varying strategies for supporting open source development. LaSuite in France has decided, for example, to create and maintain their own forks of open source software, with a consistent UI and UX. Here in Germany, ZenDiS’s approach is to fund the development and integration of existing software that’s served within a unified bundle called openDesk. There is increasing interest in using parts of LaSuite in the Netherlands, too.

• Power of integrations: The hackathon highlighted the value of integrations in making tools work together seamlessly. These integrations not only enhance user experience by reducing friction when trying to use multiple open source software but can also lead to higher adoption and user satisfaction.

What next?

We were thrilled to take part in the hackathon and were impressed with both what the other teams developed and how well organized it was. We would like to once again thank the LaSuite team for organizing such an inspirational event and for bringing so many like-minded people and companies together! We truly believe that open source is more powerful when we all work together.

We were also pleasantly surprised by the interest in our Docs–OpenProject integration.

What we worked on in the hackathon was of course an incomplete proof of concept, but we certainly don’t expect to leave things at that. We are currently exploring ways to integrate BlockNote more generically with OpenProject and will also evaluate where we can take our integration with Docs.

You will surely hear more more about this from us very soon.