Что такое Laravel Pipeline?

use Illuminate\Pipeline\Pipeline;

$result = app(Pipeline::class)
    ->send($order)
    ->through([
        ValidateOrder::class,
        CalculateTotal::class,
        ApplyDiscount::class,
        ProcessPayment::class,
    ])
    ->thenReturn();

// Каждый шаг
class CalculateTotal {
    public function handle(Order $order, Closure $next): mixed {
        $order->total = $order->items->sum('price');
        return $next($order);
    }
}

Pipeline = Chain of Responsibility. Laravel middleware работают именно так. Полезно для обработки заказов, ETL, конвейеров трансформации.