Here is a 1-paragraph summary of the text: Caching is an essential strategy for improving application performance, reducing infrastructure costs, and delivering better user experiences by storing frequently accessed data in a temporary storage layer called a cache. A cache can be set up using various tools such as Redis, which is an open-source key-value store that can process hundreds of thousands of operations in a second with sub-millisecond latency. Caching can be used to speed up database calls, reduce load on primary databases, and improve user interactions by storing expensive queries, computed results, and static assets in the cache. By identifying slow or repeated database operations using tools like Sentry, developers can spot opportunities for caching and verify performance improvements, ultimately optimizing their infrastructure and reducing costs.