The European Commission's preliminary finding on TikTok’s addictive design from last month might be a game-changer for protecting users’ digital well-being under EU law. The Commission’s focus moves beyond illegal content on the platform to the design of the platform itself. For the DSA to make this enforceable, “digital well-being” needs to be operationalised in a way that regulators and platforms can actually measure and mitigate. This blog post begins with the Commission's findings to advance the first steps toward a theory of digital well-being within the EU platform regulation framework.