I speak for a more distributed, microservices ecosystem, but the core issue is having a “fat” E2E testing suite in the first place. Since take hours to run, it forces a “batched” testing approach where a bunch of PRs are tested together (nightly etc) and leads to very slow feedback cycles for developers. Ideally I would shift to having a very small suite of E2E tests that can be run for every PR and then have service specific api tests that test the integration of the service being changed with the rest of the system. This way you de-centralize the testing as well and are closer to achieving true continuous delivery of each change to production.