[evancordell]

We always called these "four-phase migrations". An old Stripe article used similar naming[0].

[0]: https://stripe.com/blog/online-migrations

[sarchertech]

I’ve heard that one too. I think the key insight is that you need to “stop the bleeding” (stop creating more old data that needs to be migrated) before you do any backfilling. That’s why I always called it dual writing because that’s the stop the bleeding step.