> For the complete documentation index, see [llms.txt](https://docs.serverlessapigateway.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.serverlessapigateway.com/glossary/s/scalability.md). # Scalability The capability of a system, network, or process to handle a growing amount of work, or its potential to be enlarged to accommodate that growth. Scalability is the ability of a system to handle increasing amounts of work by adding resources. A scalable system can grow to accommodate higher traffic, more data, or additional users without a proportional decline in performance. Scalability is a fundamental requirement for production API systems. There are two primary scaling approaches: vertical scaling (scaling up) involves adding more power to an existing machine (more CPU, RAM, or storage), while horizontal scaling (scaling out) involves adding more machines to distribute the workload. Horizontal scaling is generally preferred for web applications and APIs because it avoids the hardware limits of a single machine and provides better fault tolerance. In serverless and API gateway contexts, scalability is largely handled by the platform. Serverless functions scale horizontally by default, spinning up new instances to handle concurrent requests. Edge-deployed API gateways scale across the provider's global network. This platform-managed scalability removes the need for teams to implement auto-scaling policies, manage server fleets, or predict capacity requirements -- the system automatically adjusts to actual demand. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.serverlessapigateway.com/glossary/s/scalability.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.