Edge computing is a model of code execution in which computation happens at servers physically close to the end user, rather than at a centralized origin server. In the context of web development, this typically means running application logic at the distributed nodes of a Content Delivery Network (CDN), a practice that can dramatically reduce the time it takes for a server to respond to a request.
To understand why this matters, it helps to consider the traditional alternative. In a conventional web architecture, every request a user makes travels from their device to a single origin server, which may be located in one specific data center anywhere in the world. For a user in Tokyo making a request to a server in Virginia, that round trip adds meaningful latency before the server even begins processing. Edge computing addresses this by moving computation out to dozens or hundreds of geographically distributed points of presence, so that a user in Tokyo is served by a nearby node rather than one on the other side of the planet.
This approach is closely related to serverless computing, in that developers write small, stateless functions without managing the underlying infrastructure. The distinction is that serverless functions typically run in a single region, while edge computing distributes those functions globally. The specific implementation of this model is often called Edge Functions, a term used by platforms such as Vercel, Netlify, and Cloudflare Workers to describe code that executes at CDN edge nodes.
The performance benefits of edge computing extend beyond raw latency reduction. Because logic runs closer to the user, tasks like authentication, personalization, A/B testing, and request routing can be handled before a response is even fetched from an origin. This means users can receive a tailored or redirected response with minimal delay, without the origin server needing to be involved in every decision. For SEO, faster server response times contribute directly to metrics like Time to First Byte (TTFB), which is a factor in both user experience and search engine ranking signals.
Edge computing does come with constraints worth understanding. Edge environments are intentionally lightweight, meaning they typically support a subset of standard runtime APIs and impose strict limits on execution time and memory. Persistent storage and complex database operations are generally not suited to the edge, which is why edge functions are most effective for logic that is stateless or that can rely on fast external data sources. Despite these limitations, the model has become a foundational pattern in modern web development, particularly for applications that prioritize global performance and low latency at scale.