from the hardware perspective, I am not sure I can give you advice here (other maybe).
but it sounds you need to give more details about your business needs because you have a lot of
data modeling solutions in mongo that can give you this efficiency per request which can reduce resources usage.
if there is a pattern of requests from your client you can adjust your schema to be more effective,
if you want to elaborate please feel free.
I’ll give an example of what I mean: if your client requests documents with a filter on date property and they are always searching in forms whole days (1,2… 10 days) you can potentially use the Bucket pattern and reduce the number of documents processed by Mongo