Google recommends hosting website resources on CDNs or subdomains to preserve main site's crawl budget for better indexing. Googlebot caches resources for 30 days, regardless of HTTP cache settings.

Google's John Mueller confirmed that when it comes to sites that host their images (or likely other files) on an external CDN, like we do here, Google will have a separate server capacity (maybe crawl ...

Google's John Mueller in a hangout from earlier this week said that one of the myths he hears a lot is around crawling, specifically around how SEOs and webmasters define or understand crawl budget.