Dynamic Site Acceleration, often shortened to DSA, is a set of techniques that CDNs use to optimize delivery of content that cannot be cached. Static files like images or scripts are easy to serve from edge servers, but dynamic pages, personalized dashboards, or API responses must still be fetched from the origin. DSA focuses on speeding up this unavoidable leg of the journey.

Origins of DSA

The concept appeared in the mid-2000s when early CDNs like Akamai began to bundle “application acceleration” products alongside their traditional caching services. Enterprises needed faster access to dynamic applications such as e-commerce checkouts or financial dashboards, which could not simply be cached at the edge. Providers promoted DSA as a premium add-on, often sold on top of a core CDN contract. Over time, most large vendors—Akamai, Limelight, and later Cloudflare and Fastly—added similar capabilities, though often under different names.

How DSA Works

DSA uses a mix of network and protocol optimizations rather than caching. Common techniques include:

  • Connection management: keeping long-lived TCP or TLS sessions open between the edge and the origin so each request avoids the cost of a fresh handshake.
  • Route optimization: steering traffic over private or measured paths instead of relying on BGP’s default choice, which may be longer or congested.
  • Protocol upgrades: applying HTTP/2 or HTTP/3 at the edge, even if the origin only supports HTTP/1.1, so the client benefits from multiplexing and header compression.
  • Prefetching and compression: in some cases, anticipating user requests or applying on-the-fly compression to reduce payload sizes.

Together these methods aim to shorten the time it takes for a dynamic response to travel from the origin through the CDN edge to the end user.

Benefits and Use Cases

DSA can provide measurable benefits when the origin is far from users or when requests must cross multiple network boundaries. For example, a user in Asia accessing a European e-commerce backend may see lower latency when the connection rides the CDN’s optimized backbone. DSA can also reduce load on origins by reusing persistent connections, avoiding the overhead of repeated TLS negotiations.

Enterprises with globally distributed audiences, APIs under heavy load, or applications with strict performance requirements have historically been the main adopters. In these contexts, DSA helps mask inefficiencies in the broader internet and stabilizes user experience across regions.

Limitations in Practice

Despite the marketing, results are mixed. When the origin is already well connected, or close to the CDN edge, DSA often provides little or no improvement. In some of my own tests, routing through a DSA service performed no better than a standard CDN request back to the origin. In certain cases, the added processing even introduced extra delay.

DSA also cannot address slow application logic. If the backend itself takes 500 milliseconds to generate a response, shaving a few milliseconds off the transport path has little impact. Similarly, because the content is uncachable by nature, CDNs cannot apply the dramatic accelerations seen with static content delivery.

Evolution and Current Role

Over time, many DSA techniques have become part of standard CDN offerings rather than sold as distinct products. HTTP/2 and TLS session reuse are now widely available by default. Global providers also increasingly run private backbones, so route optimization is often included without a separate “DSA” label.

That shift has made the term less visible today, but the underlying ideas remain relevant. They underpin features in modern edge platforms, from connection pooling to intelligent routing. The standalone DSA product of the 2000s has largely merged into the background of everyday CDN operations.

Dynamic Site Acceleration was once marketed as a premium differentiator. Today it is better seen as a bundle of network optimizations, some of which have become standard. It can still be valuable in the right context, but its impact depends heavily on the location of users, the connectivity of the origin, and the responsiveness of the application itself.