Caching and Caching Invalidation Strategies

Performance optimization is a constant challenge for developers, and caching is one of the most powerful techniques they can apply. By temporarily storing data closer to where it’s needed, caching reduces load times, minimizes expensive operations, and improves user experiences.

Common caching strategies

Time To Live (TTL) is a caching strategy that defines how long a piece of data should remain in the cache before it expires automatically. Once the TTL period elapses, the cached data is considered stale and removed or replaced the next time it’s requested. At that point, a fresh copy is fetched from the source and re-cached with a new TTL.

TTL is ideal for scenarios where data goes stale after a specific period of time. For example, in a user authentication system, session tokens are often cached with a Time To Live (TTL) value. When a user logs into a web application, an access token is generated and cached with a TTL of 30 minutes. This means the user remains authenticated and can make API requests for 30 minutes without re-validation. Once the TTL expires, the token is automatically removed from the cache, and the user must re-authenticate or refresh the token.

TTL automates the lifecycle management of data in the cache. Developers don’t need to write custom logic to invalidate stale data. The cache system handles expiry based on a timer. This reduces complexity and ...