Learn how to build and scale operational data layers effectively in this 15-minute conference talk. Explore the challenges of scaling streaming systems to handle increasing data volumes while focusing on the critical role of operational data layers as both sources and destinations. Discover how to create a global source of truth for aggregated data from internal sources, essential for additional processing and operational business intelligence. Break down the concept of scalability into specific components applicable across different scenarios, gaining practical insights into designing truly scalable systems. Master the fundamentals of operational data layers that serve diverse workloads efficiently, whether building one from scratch or optimizing existing infrastructure.