This makes per-request performance a very important aspect of the overall user experience. But any time spent optimizing the response time for assets means less time spent optimizing the bits that make your site unique. This is where a CDN comes into play, to make asset delivery somebody else's problem, both in response time optimization and in capacity allocation. The origin website focuses on producing content while offloading the part which is cacheable to the CDN. This usually represents the bulk of traffic and often includes some types dynamically-generated content besides purely static files.
A CDN may work in a different number of ways. Stratus in particular works as an architecturally and geographically distributed reverse proxy cache pulling files from your site over HTTP when first requested by a user's browser. Once cached at one of our locations, files are served as many times as needed to any user that requests them.
To ensure fast delivery of content, Stratus is designed to handle much more concurrent user connections, requests and network transfer rates than a typical website can, be it over HTTP or HTTPS. This is the core of what it provides, but you also get protection from request surges and content-control features. We'll take a more detailed, and technical, look into them in later posts.