If your services need a shared, implicit understanding of types, you're not respecting the microservice boundaries. Each microservice needs to offer a contract

If your services need a shared, implicit understanding of types, you're not respecting the microservice boundaries. Each microservice needs to offer a contract describing what inputs it accepts and immediately reject a request that doesn't meet that contract. Then type mismatches becomes very obvious during development when you start getting 400s when testing against the DEV endpoint. Don't pass around opaque structs.