Thanks for the response. Just trying to expand my brain here =), so I have a followup question.

I always thought of memoization as storing the parameters to, and result of, a function call in a memotable. Doing some quick research, I came across this definition of memoization from NIST that sounds more general "Save (memoize) a computed answer for possible later reuse, rather than recomputing the answer." What I understand from what you said is that when a request is processed, it produces a map that is passed around for the duration of the request.

Something like:

Request -> (some processes) -> memoized map -> Policy Filters

How is the memoized map reused?