dont have any specific caching strategies for user-generated content, but maybe you could cache recently viewed items?

hey everyone, im working on a platform with a lot of user-generated content (posts, comments, etc) that gets updated frequently. we're looking at implementing caching to improve read performance, but im struggling with the best approach. should we go with client-side caching, cdn, server-side caching (like redis or memcached), or a hybrid? what are your experiences with invalidation strategies for rapidly changing data? any specific trade-offs we should be aware of for this kind of use case?