Real-time user interfaces (UIs) are becoming increasingly essential for modern applications, yet their development remains complex due to the traditional client-server model. Sync engines like ElectricSQL, which utilizes Postgres logical replication, have emerged to simplify this process by handling state synchronization between clients and servers. TanStack DB, developed in partnership with ElectricSQL, offers a framework-agnostic solution for implementing real-time and optimistic updates in UIs by managing data prefetching, server-sent changes, and user action responsiveness. This combination allows for seamless multi-device and collaborative experiences without altering an app's existing backend architecture. TanStack DB supports various frontend frameworks and works with REST and GraphQL backends, offering a simplified approach to real-time application development. Currently in beta, TanStack DB and ElectricSQL together present a promising solution for scalable, maintainable real-time applications by turning Postgres into the source of truth for state synchronization.