I used to believe this too, but the more I have done online migrations, the more I think its actually the same amount of work in most cases, and less work in th

I used to believe this too, but the more I have done online migrations, the more I think its actually the same amount of work in most cases, and less work in the worst cases, and almost never more work. All the steps you have to take here, you have to do anyways. Write to new, read from new, how to translate, deleting old code. It all is the same. The only difference is you do it in chunks vs all at once. Its perception. But all the components and architecting happen anyways. Sure, you pay the cost of watching more deployments, but you also gain every step being automated, where offline migrations are often ran once, never committed. Offline migration are, like online, not free. If you have to take downtime, its usually not during business hours. You have probably quoted a downtime range to customers. So you have a window of time. You will be stressed. You will "practice", you will write a "plan". Even if everything goes well, those aren't free. But in the worst case, now you have more problems. Let's say something went wrong. Some customer data wasn't as you expected, you have to bring services back up in 20 more minutes. Do you scramble and try to fix it, late at night with limited staff? Or do you roll back? If you roll back, then you have to do this all over again, but you probably need to wait at least a week, because no one wants two planned outages back to back. With online, every step is "safe". So if you have bugs, no worries, the old way is still working! Maybe rollback the code, but no need to rollback the migration, just leave it in its current state. Take your time, fix it, dont move on till its working. But even if that doesn't convince you, the number one reason to do online migrations: No more late night planned outages. Do everything during business hours. My employer doesn't get to intentionally make me work when I should be sleeping. If that means less features shipped, then so-be-it.