The Matrix Conference 2026

When messaging across interoperable platforms or different clients in a decentralized network, there is a common set of functionalities defined by the common protocol or API bridging the conversation, but there may also be unique functionality exclusive to each client. These differences may sometimes have important implications in the user experience and privacy of the conversation partners, but there are no design patterns or agreed standards for dealing with them. For example, imagine that someone sends a "view only once picture" but the receiver's client lacks this functionality: would you expect the receiver to simply show the picture? To show an error message saying "message not supported"? Or should the sender client prevent the use of "asymmetrical functionality" in the first place?

In this design workshop, we will introduce the concept of "seamful design", briefly present cases where asymmetrical functionalities may harm user experience, and engage all attendees in a prototyping activity to explore potential workarounds through design. Based on the prototyped design ideas, we will discuss trade-offs, challenges and potential best UX practices for designing around functional asymmetries in interoperable messaging.

This talk is about how feature asymmetries between interoperable messaging apps may disrupt users' online self-presentation, that is, how they choose what features to use with different groups of people to control the impression they form of them.
Most users of messaging apps have their strategies to uphold some specific “persona”, if it is sending GIFs to add a humorous tone to the conversation, intentionally using dots at the end of messages to seem more intelligent or professional in front of their boss, or how they resonate when choosing a Snapchat avatar versus their profile picture for Teams. However, in interoperable messaging, some features are sometimes presented in different ways across clients. For example, one app may offer the sender to react to messages with an emoji, so they can reply to messages fast and with low effort, but the receiver app may attach animations to these reactions, bringing a more effortful and playful tone to the conversation. So how do these asymmetries affect users' self-presentation, when may they experience a conversation differently to how the receiver sees it? In this talk, I present a research study on how feature asymmetries across different protocols and clients may affect self-presentation and what this means for interoperability as a means for mitigating network effects.