Overview
Annotated
Mobile Push Notification Service
ingest → dedup → fanout → APNs/FCM · 70K device-sends/s peak · one 50M broadcast drained in ~11 min
arrows
0/22
cards
15
letters
A–L
happy-path
side-effect
failure-comp
new-infra
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BOTE — canonical numbers
(every N- chip in the rail links here)
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Failure playbook (A–L)
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What breaks first · interview framing