I agree with most of the points, but I have serious caveats on the first two. 1. No, the engineers should not by default be on call; the owners of the product

I agree with most of the points, but I have serious caveats on the first two. 1. No, the engineers should not by default be on call; the owners of the product are the first call line. If they're not engineers or if they're engineers but don't have enough time to deal with all incidents–in short, if they need to delegate–they better be willing to pay very generously for the extra hours of on call duty. 2. No, hosted is not better than open source, both for philosophical and operational reasons: mostly, you become subject to the whims of the provider. A good compromise is hosted open source solutions, which at least takes you half way to a migration, if the need for one comes up. That aside, I very much agree on everything else.