Cross-Cutting Concerns Are Back, and the AI Stack Is Abusing the Gateway Pattern

Some architectural problems do not stay solved. They come back every time the system grows by an order of magnitude, with the same root conditions in a more demanding form. Cross-cutting concerns are one such problem.They were named decades ago, in the era of aspect-oriented programming. They were resolved at the network layer over the 2010s, when API gateways absorbed authentication, rate limiting, observability, and policy enforcement from every microservice and moved them into a shared infrastructure layer.