How to perform event action for Catalog Product after delete completed?

You can perform event action to successfully Product deleted in Magento 2 by the catalog event name catalog_product_delete_after_done. This is the perfect event for product delete observer.

If Magento is sync with a third party ERP system and wants to sync product data between two platforms, if product deleted in Magento and want to delete a product from the ERP, You can perform this action using Magento native Event catalog_product_delete_after_done.

You can see the native Magento event declaration from the Model file, Magento/Catalog/Model/ResourceModel/Product with method name delete($object).

Create an Event in adminhtml area by events.xml file,
app/code/Jesadiya/Erp/etc/adminhtml/events.xml

<?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="catalog_product_delete_after_done">
        <observer name="custom_erp_delete_product" instance="Jesadiya\Erp\Observer\ProcessProductAfterDeleteEventObserver" />
    </event>
</config>

Create an Observer file,
app/code/Jesadiya/Erp/Observer\ProcessProductAfterDeleteEventObserver.php

<?php
namespace Jesadiya\Erp\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;

class ProcessProductAfterDeleteEventObserver implements ObserverInterface
{
    /**
     * Call an API to product delete from ERP 
     * after delete product from Magento
     *
     * @param   Observer $observer
     * @return  $this
     */
    public function execute(Observer $observer)
    {
        $eventProduct = $observer->getEvent()->getProduct();
        $productId = $eventProduct->getId();
        if ($productId) {
            //Call API to remove from ERP
        }

        return $this;
    }
}

In Observer file, You got the product id which was the latest product delete from the Magento.

This event is used to remove product-specific data once the product is deleted from the Magento instance.

You can explore the real-time example from the Review Module with admin events in native Magento.

You can also interested in seeing A Complete List of all events in Magento 2.