Transactions and Consistency

Ensure multi-step changes are atomic; make retries safe.

Commands

DB::transaction(function () use ($order, $payload) {
    $order->update([...]);
    $order->items()->createMany($payload['items']);
    OrderUpdated::dispatch($order);        // or flag for after-commit
});

// Listener queued after commit
class SendInvoice implements ShouldQueue {
    public $afterCommit = true;
}