Ask Your Dev Team how they handle data migrations

At some point, your developer is going to need to move or restructure your data. When that happens, you want to know they have a plan.

What is a data migration?

Your software stores information in a database: user accounts, orders, settings, content, everything your application needs to function. A data migration is the process of changing how that data is organized or moving it from one place to another.

This happens more often than you’d think. Maybe your developer needs to split one database table into two. Maybe you’re switching to a new payment provider and the transaction records need to be reformatted. Maybe the application has grown and the original data structure can’t keep up.

Think of it like renovating a warehouse while the inventory is still inside. You’re reorganizing shelves, relabeling boxes, and moving stock around, all without losing a single item.

What can go wrong

Data migrations carry real risk. Here’s what’s at stake:

• Data loss: Records can be dropped, duplicated, or corrupted during the move. If a migration fails halfway through, you could end up with incomplete data.
• Downtime: Some migrations require taking the application offline. That means your users can’t access the product while the work is happening.
• Broken references: Your data is connected. A user has orders. An order has line items. A line item references a product. If one piece moves and the connections don’t follow, things break in ways that aren’t always immediately visible.

These aren’t hypothetical problems. They happen regularly to teams that don’t plan for them.

What to ask

“Do you have a rollback plan?” This is the most important question. If a migration fails or produces unexpected results, can they undo it? A developer without a rollback plan is gambling with your data.

“How do you test a migration before running it in production?” The answer should involve running the migration against a copy of your real data in a safe environment first. If they’re testing against fake data or not testing at all, that’s a problem.

“How do you minimize downtime?” Some migrations can be done in the background while the application is still running. Others require a maintenance window. Your developer should be able to explain which approach applies and how long users will be affected.

“How do you verify the migration was successful?” After the migration runs, there should be a validation step. Counting records, checking key relationships, and confirming that the application works as expected with the new data structure.

Don’t assume it’s routine

Developers run migrations regularly, and most go smoothly. But “routine” doesn’t mean “risk-free.” The teams that handle migrations well are the ones that treat every migration like it could go wrong, because eventually, one will.

A clear plan, a tested process, and a rollback strategy are the minimum. If your developer can walk you through all three without hesitation, you’re in good hands.

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