Here’s an interesting article about Uber’s use of service oriented architecture (SOA).
As core domain models grew and new features were introduced, our components became tightly coupled, and enforcing encapsulation made separation of concerns difficult. Continuous integration turned into a liability because deploying the codebase meant deploying everything at once. Our engineering team experienced rapid growth and scaling, which not only meant handling more requests but also handling a significant increase in developer activity. Adding new features, fixing bugs, and resolving technical debt all in a single repo became extremely difficult. Tribal knowledge was required before attempting to make a single change.
Service-Oriented Architecture: Scaling Our Codebase As We Grow