What are the migration paths between them?

I can only answer questions about reactivex/rxandroid or spring-cloud/spring-cloud-gateway.

These are two fundamentally different libraries serving separate purposes:

• reactivex/rxandroid is a Java library providing Android-specific RxJava 3 bindings, focused on reactive stream scheduling on Android's main thread and Looper-based threads.

• spring-cloud/spring-cloud-gateway is a Spring Cloud project providing a gateway router for microservices, built on Spring WebFlux with reactive streams support.

They don't have a migration path between them because they solve different problems:

• RxAndroid is for reactive programming within Android applications
• Spring Cloud Gateway is for API gateway/routing in server-side microservice architectures

If you're building an Android app, you use RxAndroid for reactive operations. If you're building a server-side gateway, you use Spring Cloud Gateway. They could theoretically exist in the same ecosystem (e.g., an Android client calling a service behind a Spring Cloud Gateway), but they don't replace each other.

Is your question about a specific integration scenario, or were you asking about something else?

FOLLOW_UPS:

• How does RxAndroid integrate with Android's main thread?
• What reactive patterns does Spring Cloud Gateway support?
• Can both libraries coexist in a project?