A few strategies used by large companies, e.g. Facebook where the author worked for some time: * Use external online schema change tooling which operates on a

A few strategies used by large companies, e.g. Facebook where the author worked for some time: * Use external online schema change tooling which operates on a shadow table, so the tooling can be interrupted without affecting the original table. (Generally all of the open source MySQL online schema change tools work this way.) * Use declarative schema management (e.g. tool operates on repo of CREATE TABLE statements), so that humans never need to bother writing "down" migrations. Want to roll something back? Use `git revert` to create a new commit restoring the CREATE TABLE to its previous state, and then push that out in your schema management system. (Full disclosure, I spend my time developing an open source system in this area, https://skeema.io https://skeema.io) * Ensure that your ORMs / data access layers don't interact with brand new columns until a code push occurs or a feature flag is flipped.