Or because rollbacks (and release) are slower than flipping a flag.

I’d rather invest in the feature flag upfront so I can unbreak customers in 2min rather than telling them to wait hours for the rollback.

Why are rollback and release so slow? Because we’re deploying to 40+ availability zones world-wide, totaling many thousands of servers, and we don’t want to worsen the impact by doing an accelerated “everything-at-once” rollback.