While an infrastructure can, in theory, have any number of tiers, by far the most common pattern is the 3-tier infrastructure. 

This article describes:

Simplifying AWS Global Connectivity with Transit Gateways

Since this blog post was initially published, AWS has released new features available in the 3-tier infrastructure. Read the updated version here.

As part of the AWS Best Practices series of posts we will talk about various topics from migration to tagging to security. Here we will discuss the 3-tier architecture pattern.