Why am I getting misses, isn't Fastly caching my content?

There are many things that can cause a MISS. If you are sending cookies, thus have the Set-Cookies header, that will pass Fastly and go directly to your origin server. Also, there are certain Cache-Control parameters that will also cause the request to bypass Fastly and go directly to the origin. For example setting maxage=0, no-cache, ‘must revalidate’, ‘no-store’, private, all bypass the Fastly cache and create the MISS.