Good article, but it's a bit binary on the notion of incident. For the same company, it can be very serious to have a global 1h outage, but not so serious to have the internal admin interface down for 1h. This allows for more fine-grained assessment of the validation required to push to prod: the "checks" only have to test the critical part of the application. Dev exp start deteriorating when the non-critical parts are over-tested.