I added more details in the me.ReadMe solution file, but to reiterate, the cache portion is theoretically working code, but lacks unit tests and I have not created integration tests across the whole thing. Ideally I'd like a few more days to refine, expand, and tinker; but given the stated goals of the test I think it's a good reflection of a couple days' thought and about 8 hours of work. I need Sunday for chores and a little down time before the next week of work, so I am submitting in its current state.

I look forward to getting your thoughts and having the chance to talk about the whys and decisions made when working through the challenge.