Optimistic UI is a technique where you update the UI immediately, assuming the server call will succeed, and only roll back if it fails.
When a user clicks 'Like' or 'Delete', don't show a loading spinner. Update the local state instantly. In the background, send the API request. If the request succeeds, do nothing. If it fails, show an error message and revert the local state. This makes your Blazor app feel as fast as a native desktop application.
Use a Guid as a temporary ID for newly created objects on the client. When the server returns the real database ID, update your local collection. This ensures that the user can keep interacting with the 'New' object even while it's still being saved to the database.
Q: "Is Optimistic UI dangerous?"
Architect Answer: "It requires careful error handling. You must have a robust way to 'Undo' the local change. It's also not suitable for critical operations like 'Place Order' or 'Transfer Funds' where accuracy is more important than perceived speed. Use it for 'Social' or 'Preference' style updates."