Are you versioning your api? I assume the clients are communicating with the server via some sort of api. Document the api in machine-readable form (like, say,

Are you versioning your api? I assume the clients are communicating with the server via some sort of api. Document the api in machine-readable form (like, say, Swagger), and have separate test suites for both client and server, to specific api versions. Since both are working against the same (complete and consistent!) spec, they should be able to talk to each other, and integration testing can be pretty minimal. For REST apis, use semantic versioning, and you can embed specific versions in the request headers. The server should be able to respond correctly to a range of different versions (an api call to say what range of versions the server speaks isn't a bad idea). Coarse-grained api revisions can be embedded in the url (the ever popular /v1 and /v2, etc).