Functional programming values immutability, but most systems still rely on mutable databases that introduce complexity and fragility. Datomic offers a different path: an immutable, time-aware database that aligns with functional programming principles while delivering real-world scalability and flexibility. In this talk, we’ll explore how Datomic’s immutable model enables composable data pipelines, simplifies debugging with time-travel queries, and supports dynamic, evolving schemas. Whether you’re building for finance, e-commerce, or beyond, this talk showcases how Datomic turns functional ideals into production-grade realities.