API Gateway — Part 3: Advanced Concepts, Anti-Patterns & Comparisons

What is this?

By now you can explain what a gateway does and how it works inside. This part is about judgment — the stuff that separates someone who can name a gateway from someone who can architect with one.

Think of it like the difference between knowing what a kitchen knife is and being a chef. The chef knows when a knife is the wrong tool (you don't carve a turkey with a paring knife), where it overlaps with other tools, and which mistakes ruin a dish. This chapter is the chef's knowledge for gateways: how a gateway differs from a load balancer and a service mesh, how it works alongside them, the deployment patterns that ship changes safely, and the anti-patterns that quietly wreck real systems.

The one-line idea: the gateway is one piece of a larger picture — knowing where it ends, where the load balancer and service mesh begin, and which "clever" uses of it are actually traps is what turns gateway knowledge into architecture skill.