So I've been looking into microservices communicating with a persistent message broker like Kafka and what I'm still not sure about is the frotnend - that is, I

So I've been looking into microservices communicating with a persistent message broker like Kafka and what I'm still not sure about is the frotnend - that is, I know that the FE will communicate over https with an API gateway service (so REST or GraphQL) but if the FE needs a resource, how should the API gateway handle the request back to the browser? The only pattern I've seen so far is to issue a 201 CREATED for e.g. creating a user. Have you come across any other patterns for this?