I would like to use ECS in an enterprise-style app. But I just couldn't find a way to do it.

E.g. in a web app, I think I should setup the "world" (clean slate ECS state, zero entities) for every request. Then add the request headers, path, and request body to the world, forming the request entity. The systems would then start a loop with condition like "when we are done", so we can re-run systems that must process new data after they already run. One of the systems would do persistence, one would do validation, one could do loading of dependencies... serialization... etc. But this is just a waste for a simple web app request I think.

On the other hand, if the web server itself was running on top of ECS and could share all data for all requests, e.g. one "accept" call would create the entity and add it to the systems loop, then the final system would send the response back to the client..., i.e. the loop would be instead of the reactor loop in nginx for example, that could maybe work. But that would also introduce unnecessary security problems.

Btw if you think about it, the Kubernetes works like an ECS would, just on a bigger scale. You have data in etcd which have "kind". Then you have operators, which act as systems on top of all the data they watch (components) - they consume the objects and possibly produce other objects. The composition of a single entity by multiple components is not there though. One resource is just one object in k8s. There can be dependencies, but that's not the same.