This is a submission for the Google Cloud NEXT Writing Challenge During the developer keynote at Google Cloud NEXT '26, a GDE demoed FinnishIt: an AI-powered Finnish language tutor built on the GenUI SDK for Flutter. You give it a topic, it asks refining questions, then generates a custom deck of interactive flashcards specific to that context. Role-play scenarios shift from text to tap-and-drag word puzzles to fill-in-the-blank modules depending on what the AI determines you need right now. Every session produces a different interface. That's the point where I stopped treating A2UI as conference noise and started paying attention. A2UI is an open standard Google donated to the community at NEXT '26. It lets agents generate UI dynamically at runtime. The GenUI SDK for Flutter is the developer-facing layer that makes it practical to build with. Most coverage either skipped it or described it without asking the more useful question: when does this actually make sense to use?…