Checkout request execution

Illustrative timing: inventory lookup and discount calculation run concurrently; payment follows.

Checkout request execution Illustrative timing: inventory lookup and discount calculation run concurrently; payment follows. Illustrative timing Wall-clock 1,200 ms0 → 1,200 ms Operation 0 ms 200 ms 400 ms 600 ms 800 ms 1,000 ms 1,200 ms POST /checkout · 0–1,200 ms · 1,200 ms · 100% of 1,200 ms wall-clock — Parent of every step below; its duration is not added to theirs. · checkout-api POST /checkout 1,200 ms Authenticate caller · 0–100 ms · 100 ms · 8.3% of 1,200 ms wall-clock · identity › POST /checkout Authenticate caller 100 ms Look up inventory · 100–400 ms · 300 ms · 25% of 1,200 ms wall-clock · inventory › POST /checkout Look up inventory 300 ms Calculate discount · 100–300 ms · 200 ms · 17% of 1,200 ms wall-clock · checkout-api › POST /checkout Calculate discount 200 ms Charge payment · 400–1,050 ms · 650 ms · 54% of 1,200 ms wall-clock · payments › POST /checkout Charge payment 650 ms Write order · 1,050–1,200 ms · 150 ms · 13% of 1,200 ms wall-clock · checkout-api › POST /checkout Write order 150 ms Legend checkout-api identity inventory payments