I don't know of company-wide policies like that (though I'm sure that they exist -- and I do know of individual teams that have such policies), but I do know of

I don't know of company-wide policies like that (though I'm sure that they exist -- and I do know of individual teams that have such policies), but I do know of many projects which have such policies (for instance, all of the Open Container Initiative projects require two approvals from maintainers other than the author).