Matrix Conference 2025

In this talk, we’ll take you through the real-world journey of developing and approving a TI-Messenger - a secure, interoperable messaging application built on top of the Matrix protocol for use within Germany’s healthcare system. What began as am idea soon grew into a tightly regulated, multi-stakeholder project, with high demands on privacy, trust, and compliance.

This session is less about features and more about transformation. It’s a case study of how we shaped a Matrix-based messenger to meet the strict security, interoperability, and governance requirements defined by the gematik specification, and how that shaped our development process in return. Unlike general-purpose Matrix clients, the TI-Messenger is deeply constrained by legal frameworks, security audits, and standardized certification making the path from concept to approval full of unique challenges.

We’ll reflect on what we learned about applying Matrix in high-trust environments, what we would do differently, and how our experience could inform similar efforts elsewhere. Whether you’re working in the public sector, healthcare, or simply curious how Matrix can scale to more regulated use cases, this talk offers an inside look at what it takes to make Matrix meet mission-critical standards.

Open Source has never been easy, but doing Open Source in the Matrix ecosystem poses a unique set of challenges. Add the pressure of sustaining a company on top of that, and you quickly find yourself in uncharted, and often uncomfortable, territory. This talk reflects on the reality of maintaining open source projects in the Matrix universe, especially from the perspective of a business. It dives into the tension between openness and exploitation, when others take your work without contributing anything in return, undermining sustainability and motivation.

Through real-world experiences and hard-learned lessons, this session will outline the structural and cultural issues that make it harder for corporate contributors to survive in the ecosystem. We'll look at why fair contribution is hard to enforce, how "Trittbrettfahrer" (free riders) hurt long-term progress, and what we as a community - maintainers, companies, and individuals - can do to shift the dynamic. Whether it's licensing strategies, community governance, or pushing for upstream responsibility, this talk will explore the imperfect but necessary mechanisms we need to keep Matrix open, but not exploitable.

The goal isn't to complain, but to open up a grounded and honest discussion about sustainability, fairness, and the future of open collaboration in Matrix.

Trixnity is rapidly emerging as a powerful, flexible, and fully asynchronous SDK for building Matrix applications using Kotlin Multiplatform. What many don't realize: Trixnity is already in widespread use - potentially powering apps usable by over 50 million people. It’s embedded in multiple Matrix-based messengers, though you’d only know it by digging into app license disclosures. This talk shines a light on Trixnity’s hidden but significant role in the Matrix ecosystem and why more developers should pay attention. This session also presents the current state of Trixnity in 2025, highlighting key milestones, recent developments, and its growing adoption in real-world applications.

Tammy is a multiplatform Matrix Messenger designed to be redefined by you. Want a different room list layout? Need a messaging interface tailored to a specific use case? Tammy’s extensible architecture makes that not only possible - but easy. In this talk, we’ll showcase how Tammy empowers developers to create radically customized Matrix experiences through its extension system.

We’ll walk you through how we’re using Tammy to build Timmy, a TI-Messenger variant tailored for a very specific user group, with a completely different look and feel - all without forking or rewriting the core client.

Expect a live demo, some under-the-hood insights, and a glimpse into the roadmap: spaces, audio/video, Matrix 2.0 and more. Whether you want a more focused UI, a minimalist mobile mode, or something wildly experimental, Tammy gives you the tools to build it.