what are your go-to patterns for cache invalidation

lately we've been adding a lot of caching to our read-heavy services. getting data into the cache is one thing, but keeping it fresh, wow, that's a challenge. time-based expiration usually isn't granular enough. cache-aside is pretty common, but what happens when the actual data changes, you know? what are your go-to patterns or strategies for reliably clearing out cache entries when the main data gets updated? and are there any architectural setups that make this whole process simpler