In this presentation, we explore the concept of knowledge databases, which represent entities and their relationships in a structured and semantic way. By combining this model with immutability—where data is never overwritten, only accumulated—it becomes possible to build systems with a complete, auditable history and native versioning. This approach is particularly powerful in complex ecosystems like Nubank’s, where thousands of microservices interact. We’ll show how modeling these interactions as a knowledge database allows us to uncover patterns, dependencies, and insights that are otherwise hidden, ultimately helping teams understand and evolve the system more safely and intelligently.
Biography
Darlei Soares and João Nascimento are software engineers and data enthusiasts with deep experience in building systems around immutable knowledge databases. Currently part of the engineering team at Nubank, Darlei and João both work on designing and maintaining highly distributed services that leverage Datomic at scale, powering financial operations for millions of customers.
Recorded Nov 13, 2025 at Clojure/Conj 2025 in Charlotte, NC.
Vanilla OS is not your regular Linux distribution, we define it as a Linux based operating system due to the new paradigms it introduces and the different standards it follows. This page explains what Vanilla OS is and how it is different from other Linux distributions.
Flatcar Container Linux is a container optimized OS that ships a minimal OS image, which includes only the tools needed to run containers. The OS is shipped through an immutable filesystem and includes automatic atomic updates.
