Caching & Delivery
Keep a hit rate above 90% while writes arrive. Serve one stale value to the wrong reader and you lose the round.
The cache tier restarts under full traffic. Keep the database alive.
Place content across twelve regions under a fixed budget and a shifting traffic map.
Move a 4 GB file from a flaky phone to an object store, twice, without paying for it twice.
The other tracks
The machine and the network under every diagram · 5 modules · 23h
Where the state lives, and what it costs to keep it · 6 modules · 30h
Decoupling two services without losing a message · 5 modules · 21h
From one box to a fleet, without a rewrite · 5 modules · 17h
What happens on the worst day · 5 modules · 18h
The six systems you will actually be asked to draw · 6 modules · 22h
Running the forty-five minutes on purpose · 5 modules · 12h
