Europe is highly dependent on US cloud services. Until recently that was not a problem, but geopolitical shifts have made it risky. Technological sovereignty sounds nice, but how do we achieve it? Being able to easily move from one provider to another is an important part of the story. In this keynote Martin Kleppmann will talk about two technological trends that he has helped kick off, and that both aim to enable easy provider switching for different domains: local-first software (for collaborative tools) and the atproto ecosystem around Bluesky (for social media).