This is an interesting read about the history of the EBS subsystem in Amazon EC2. This quote particularly stands out to me:
What I didn’t realize until I joined Amazon, and seems obvious in hindsight, is that you can design an organization much the same way you can design a software system. Different algorithms have different benefits and tradeoffs in how your organization functions. Where practical, Amazon chooses a divide and conquer approach, and keeps teams small and focused on a self-contained component with well-defined APIs.