You still have to use their SDKs to write lots of integration tests (they call them “workloads”). Then they run those tests while injecting all sorts of failur

You still have to use their SDKs to write lots of integration tests (they call them “workloads”). Then they run those tests while injecting all sorts of failures like OS failures, network issues, race and timing conditions, random number generator issues, etc. It’s likely the only practical way today of testing for those things reliably, but you still have to write all of the tests and define your app state.