Cloud migrations fail loudly when the sequencing is wrong — moving the wrong component first, underestimating a dependency, or not having a tested way back if something breaks mid-migration. None of these are cloud problems; they're planning problems that show up during a cloud migration.
Start by mapping dependencies, not just inventorying servers. The question that matters is which systems must move together because they talk to each other constantly, and which can move independently. Migrating a tightly coupled system in pieces is one of the most common causes of unplanned downtime.
A rollback plan is not optional, and it needs to be tested before migration day, not designed on the day something goes wrong. If you can't cleanly reverse a migration step, that step needs a different, more conservative approach — usually running old and new in parallel briefly rather than a hard cutover.
The migrations that go smoothly almost always move in a deliberate order: stateless, low-risk components first to validate the process, then progressively more critical systems, with monitoring in place at every stage to catch a problem within minutes rather than discovering it from a customer complaint.
