HTTP caching is a simple concept: serve cached responses if available, otherwise fetch and cache the response. Cache revalidation helps prevent too many requests from going to the origin server at once. A new approach uses probability to determine when to revalidate the cache. This approach can adapt to changing request rates and reduce the number of requests sent to the origin server, preventing cache stampede. The code implements this approach using a probabilistic function that increases over time as the expiration gap approaches, ensuring low latency and high performance while maintaining optimal cache utilization.