Editing Openai/696e35f8-9d68-8009-a35a-26169c8ccbe9 (section)

==== 1. Fire-and-Forget Optimistic Updates (Baseline / Minimal Control) ====

Complexity: ⭐
When to use: Small apps, low concurrency, low correctness requirements

===== Core idea =====
* Apply optimistic updates immediately in the UI.
* Send API requests immediately.
* Server responses eventually reconcile state.
* No attempt to serialize or block conflicting user actions.

===== API calls =====
* POST /todos – create
* PATCH /todos/:id – edit
* DELETE /todos/:id
* PATCH /todos/reorder

Calls are sent immediately on user action.

===== How it handles fast user edits =====
* Client-generated temporary IDs (e.g. temp-123) are used for new todos.
* When server responds, temp IDs are replaced with real IDs.
* Reorder operations are sent assuming optimistic state is correct.

===== How bugs happen =====
* User edits a todo before the server returns → edit sent with temp ID → server rejects.
* Reorder is computed from optimistic order → server applies it to stale order.

===== Mitigations (still simple) =====
* Retry failed requests
* Full list refetch after errors
* Disable editing of newly-created todos until server responds

⚠️ Still fragile under rapid interaction.