Containers started as a deployment trick: bundle your code with dependencies, ship it anywhere, run it everywhere. That worked well, but it only told half the story. The other half emerged when engineers stopped viewing containers as delivery mechanisms and started treating them as composable building blocks that could work together.

This shift mirrors what happened in the 1990s with object-oriented programming. OOP gave developers clean boundaries around code that could be composed and reused. From that came design patterns—standard solutions to problems programmers faced repeatedly. Distributed systems are now experiencing the same evolution with containers.

The article outlines six patterns that have crystallized over the past decade. Three address how containers cooperate on a single machine, while the other three handle coordination across many machines. These aren't rigid rules—they're answers to problems that distributed-systems engineers keep solving over and over.