Martin Kleppmann, author of Designing Data-Intensive Applications and associate professor at Cambridge, discusses two major trends in data systems: the shift from monolithic databases to modular cloud-native building blocks, and the movement toward user data sovereignty. He explains the AT Protocol underlying BlueSky, which balances decentralization with a consistent user experience by using Personal Data Servers and a global firehose aggregator, allowing users to switch providers without losing data. He then dives into the local-first software movement, which advocates storing the primary data copy on the user's device to enable offline access, faster performance, and resilience against service shutdowns. Kleppmann highlights Automerge, an open-source Rust library with bindings for TypeScript, Swift, Java, Python, and Go, that enables real-time collaboration and Git-like version control for non-text formats like spreadsheets and CAD files. He also discusses limitations of local-first (not suitable for authoritative server data like bank balances), retrofitting existing apps, and the growing local-first conference community.
