> 90% of the cases are easy cases I'll second this. For example, I can usually get away with simple and short lived TTL caches in varnish (with grace) for high

> 90% of the cases are easy cases I'll second this. For example, I can usually get away with simple and short lived TTL caches in varnish (with grace) for high traffic read only APIs. Flushing (invalidation) is automated since it just expires. It doesn't always fit, but often it does.