Nightly scores or live ranking

Model 01

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A shop shows 20 picks per user on its home page. Picks use only yesterday's orders and a catalog that changes once each night. Peak is 3,000 views/s. Keep p99 below 50 ms and cost below 60 USD/mo.

Goals

Not tested yet

99 of 100 requests finish faster than this.The share of requests that fail or get no answer.What the servers and services cost each month.
Choose a design
Rank 500 items on CPU at each view
Rank 500 items on a GPU at each view
Score all users each night and store picks