692: You Need Stale While Revalidate

This podcast episode explores the concept of caching and its benefits for website performance. The hosts discuss the Stale While Revalidate technique, which allows for caching while ensuring data is up to date. They provide examples of caching HTML pages and Open Graph images. Caching is valuable for reducing costly operations by storing and serving cached data. Other use cases include storing images locally and using CDNs to cache assets closer to users, thus reducing website loading times. The episode also delves into different types of caches and their advantages, including browser caching and CDN server caching. Exception handling with caching is highlighted, with a recommendation to use services like Sentry for monitoring. The role of cache headers in combination with CDNs for efficient caching and content delivery is explained, covering topics such as max age, S max age, and potential security issues. The concept of Stale While Revalidate is discussed, which allows for serving stale content while generating new versions in the background. The limitations and use cases of Stale While Revalidate are explored, emphasizing the importance of considering specific scenarios. Takeaways • Caching is a valuable technique in computer science that improves the speed and efficiency of web applications by avoiding repetitive and costly operations. • The Stale While Revalidate technique allows for caching while ensuring data is up to date, with examples including caching HTML pages and Open Graph images. • Other use cases for caching include storing images locally and using CDNs to cache assets closer to users, resulting in reduced website loading times. • Caching can exist on both the browser and CDN servers, and exception handling is important for accurate data delivery. • Cache headers play a crucial role in instructing servers and CDNs on how to handle caching, with topics like max age and S max age discussed. • Potential security issues may arise when caching sensitive information or using shared caching, so caution is advised. • Stale While Revalidate allows serving stale content while generating new versions in the background, but its effectiveness depends on website traffic. • Considerations such as high traffic, real-time updates, and CDN propagation time should be taken into account when deciding whether to use Stale While Revalidate universally. • Understanding the implications of different caching headers and their explanations is important, and revisiting other episodes for more comprehensive explorations is recommended.