Cache Warmer

After a deploy, a cache flush or a save in the admin, the Cache Warmer requests each store view's home page, categories (the top levels first), CMS pages and best sellers once, one at a time, so the full page cache holds them before the first visitor. It goes through Varnish when the store has it (http_cache_hosts) or Magento's own cache, waits while the server is busy, and gives up on a storefront that doesn't answer. bin/magento zero:cache:warm runs it at once. Needs the Zero theme (composer require zerofront/zero brings it); it doesn't work with Luma or Hyvä.