Clear all possible WP cache systems

cache.php

<?php
if ( ! function_exists( 'lets_clear_cache' ) ) {
	function lets_clear_cache() {

		// WP Rocket
		if ( function_exists( 'rocket_clean_domain' ) ) {
			rocket_clean_domain();
		}

		// W3 Total Cache : w3tc
		if ( function_exists( 'w3tc_pgcache_flush' ) ) {
			w3tc_pgcache_flush();
		}

		// WP Super Cache : wp-super-cache
		if ( function_exists( 'wp_cache_clear_cache' ) ) {
			wp_cache_clear_cache();
		}

		// WP Fastest Cache
		if ( function_exists( 'wpfc_clear_all_cache' ) ) {
			wpfc_clear_all_cache( true );
		}

		// WPEngine
		if ( class_exists( 'WpeCommon' ) && method_exists( 'WpeCommon', 'purge_varnish_cache' )  ) {
			WpeCommon::purge_memcached();
			WpeCommon::clear_maxcdn_cache();
			WpeCommon::purge_varnish_cache();
		}

		// SG Optimizer by Siteground
		if ( function_exists( 'sg_cachepress_purge_cache' ) ) {
			sg_cachepress_purge_cache();
		}

		// LiteSpeed
		if ( class_exists( 'LiteSpeed_Cache_API' ) && method_exists( 'LiteSpeed_Cache_API', 'purge_all' ) ) {
			LiteSpeed_Cache_API::purge_all();
		}

		// Cache Enabler
		if ( class_exists( 'Cache_Enabler' ) && method_exists( 'Cache_Enabler', 'clear_total_cache' ) ) {
			Cache_Enabler::clear_total_cache();
		}

		// Pagely
		if ( class_exists( 'PagelyCachePurge' ) && method_exists( 'PagelyCachePurge', 'purgeAll' ) ) {
			PagelyCachePurge::purgeAll();
		}

		// Autoptimize
		if ( class_exists( 'autoptimizeCache' ) && method_exists( 'autoptimizeCache', 'clearall' ) ) {
			autoptimizeCache::clearall();
		}

		// Comet cache
		if ( class_exists( 'comet_cache' ) && method_exists( 'comet_cache', 'clear' ) ) {
			comet_cache::clear();
		}

		// Hummingbird Cache
		if ( class_exists( '\Hummingbird\WP_Hummingbird' ) && method_exists( '\Hummingbird\WP_Hummingbird', 'flush_cache' ) ) {
			\Hummingbird\WP_Hummingbird::flush_cache();
		}
	}

	add_action( 'save_post', 'lets_clear_cache' );
}

W3C Total cache's w3tc_pgcache_flush function is marked as deprecated. I believe you want w3tc_flush_all instead.