Interesting question arises here. Given most shops are now using interpreted languages, is it possible to make a change to say a .py file and ONLY deploy that .py file to production? i.e. do incremental releases
In microservice world, you have to run e2e tests because thats the only place where you can really guarantee the system will work as you expect.
Pacts wont solve that, integration test - the same, units w/e.
Running a monolith test is overall faster than spinning 20 microservices, beinging every db to specific atate and running tests.
But I think that's definitely an interesting idea (likely with some small levels of extra caution with some specific high profile files, like an API definition/endpoint or something).