How do you handle caching for user-specific data?

hey everyone, ive been thinking a lot about caching lately, especially when it comes to data that's unique to each user. like, user preferences, personalized dashboards, or shopping cart contents. directly caching this kind of data can get complicated with invalidation. what are your go-to strategies or patterns for managing user-specific caches effectively? are there specific tools or techniques you find particularly useful for this problem