This article is a catch if you want to clean cache automatically after any admin configuration or product save.

Follow below two steps to get it done.

1. Create file event.xml on app/code/Magemonkeys/AutoFlushCache/etc

<?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="controller_action_postdispatch_adminhtml_system_config_save">
        <observer name="auto_flush_cache" instance="MagemonkeysAutoFlushCacheObserverFlushCache"/>
    </event>
</config>

2. Create file FlushCache.php on app/code/Magemonkeys/AutoFlushCache/Observer

<?php
namespace MagemonkeysAutoFlushCacheObserver;

class FlushCache implements MagentoFrameworkEventObserverInterface
{
    public function __construct(MagentoFrameworkAppCacheTypeListInterface $cacheTypeList, MagentoFrameworkAppCacheFrontendPool $cacheFrontendPool)
    {
        $this->cacheTypeList = $cacheTypeList;
        $this->cacheFrontendPool = $cacheFrontendPool;
    }

    public function execute(MagentoFrameworkEventObserver $observer)
    {
        $types = array(
            'config',
            'layout',
            'block_html',
            'collections',
            'reflection',
            'db_ddl',
            'eav',
            'config_integration',
            'config_integration_api',
            'full_page',
            'translate',
            'config_webservice'
        );
        foreach ($types as $type)
        {
            $this->cacheTypeList->cleanType($type);
        }
        foreach ($this->cacheFrontendPool as $cacheFrontend)
        {
            $cacheFrontend->getBackend()->clean();
        }
    }
}