[velox_io]

Implement cache isn't hard conceptionally. If an object is modified, flush it from cache. If object isn't cached, build it.

The problem is that implementing caching is a bit of a canary in a coal mine. If there are problems with the architecture, then trying to add caching into the mix will make things much more difficult.

I wouldn't say adding cache to parts which you know will be heavily read, upfront (or at least adding hoods to make it easier to implement later) is a waste of time or "Premature Optimisation". The 80-20 rule is live and well, just use your judgement.