Building Microservices

Chapter 10. Conway’s Law and System Design

Much of the book so far has focused on the technical challenges in moving toward a fine-grained architecture. But there are other, organizational issues to consider as well. As we’ll learn in this chapter, you ignore your company’s organization chart at your peril!

Our industry is young, and seems to be constantly reinventing itself. And yet a few key laws have stood the test of time. Moore’s law, for example, which states that the density of transistors on integrated circuits doubles every two years, has proved to be uncannily accurate (although some people predict that this trend is already slowing). One law that I have found to be almost universally true, and far more useful in my day-to-day work, is Conway’s law.

Melvin Conway’s paper How Do Committees Invent, published in Datamation magazine in April 1968, observed that:

Any organization that designs a system (defined more broadly here than just information systems) will inevitably produce a design whose structure is a copy of the organization’s communication structure.

This statement is often quoted, in various forms, as Conway’s law. Eric S. Raymond summarized this phenomenon in The New Hacker’s Dictionary (MIT Press) by stating “If you have four groups working on a compiler, you’ll get a 4-pass compiler.”

Evidence

The story goes that when Melvin Conway submitted his paper on this topic to the Harvard Business Review, they rejected it, claiming he hadn’t proved his thesis. I’ve ...