How is data caching performed when calling the API?

Data caching when calling an API is usually implemented to reduce the number of network requests and speed up the response. Main caching methods:

• Client-side cache: the browser or application stores the API response for a certain period (for example, using HTTP headers Cache-Control, ETag). On a subsequent request, the cache is checked first, and if the data is still valid, it is used.

• Intermediate cache (proxy, CDN): API requests can be cached at the proxy server or CDN level, reducing server load.

• Server-side cache: the API server can store request results in memory (for example, Redis, Memcached) for quick access.

Example HTTP headers for caching:

Cache-Control: max-age=3600
ETag: "abc123"

This means the response can be cached for 1 hour, and ETag allows checking if the resource has changed.