FlutterFlow covers a lot out of the box, but there are moments where you hit something it just doesn’t support. I had one recently, needed to clean and transform some nested JSON before displaying it. Couldn't do it with the built-in actions, so I finally reached for custom code.
Once you get the structure right (functions in custom_code, imports, return types set), it's pretty easy to drop in Dart and use it like any other action. I’ve used it for small things: date formatting, text parsing, sorting lists with logic that FF can’t express.
I’ve also learned not to overuse it. If there’s a way to solve something using FlutterFlow’s own tools, it’s usually better for long term readability. But if you're stuck, custom code gives you a clean way out without rebuilding the whole thing in native Flutter.
Would be useful to hear how far people are taking this, anyone embedding full third-party SDKs or building UI components through it? Or mostly just logic helpers like I’ve been doing?