What is an API?
An Application Programming Interface, or API, is a set of rules and protocols that allows different software applications to communicate with each other. Think of it as a messenger that takes requests from one system, processes them, and returns the appropriate response. APIs are fundamental to modern software development, enabling everything from mobile apps to complex cloud platforms to function seamlessly. They abstract the underlying complexity of systems, providing developers with a standardized way to integrate functionality without needing to understand every detail of the code behind it.
The Role of APIs in System Design
In system design, APIs are critical for building scalable and maintainable architectures. When preparing for technical interviews—such as with system design interview prep courses—understanding API design is often a key focus. APIs allow services to interact across different environments, whether on-premises, in the cloud, or across hybrid infrastructures. For example, in microservices architecture, each service communicates through well-defined APIs, which helps in isolating issues, scaling components independently, and enabling teams to work on different parts of a system concurrently. A common pattern is the RESTful API, which uses HTTP methods like GET, POST, PUT, and DELETE to
