Observer en Magento 2 para escuchar eventos clave

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="checkout_submit_all_after">
        <observer name="gdw_after_order" instance="GDW\Hello\Observer\AfterOrder"/>
    </event>
</config>

<?php
namespace GDW\Hello\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Psr\Log\LoggerInterface;

class AfterOrder implements ObserverInterface
{
    public function __construct(private LoggerInterface $logger) {}

    public function execute(Observer $observer)
    {
        $order = $observer->getEvent()->getOrder();
        $this->logger->info('Nueva orden: ' . $order->getIncrementId());
    }
}