Architecture Simulator

First Real Customers

You run a helpdesk SaaS. Support teams at other companies use it to track their tickets. You have just signed your 500th customer organisation -- roughly 25,000 end users, all in one country, all on the web app. Until last month this ran on a single box under someone's desk, and last month it fell over for four hours during a customer's own outage, which is exactly when they needed it. Your biggest customer has asked, politely, what your availability commitment is. You have $300 a month. Not $3,000. Build something you can defend.

Must meet

p99 latency: ≤ 500ms
Availability: ≥ 99.00%
Budget: ≤ $300/mo
Durability: durable
Consistency: read-your-writes

The system does

·Accounts and login

Components

Drag onto the canvas, or tap one and then tap where it goes. Not everything here belongs in every design — picking the wrong component is part of the exercise.

TrafficTuesday afternoon · 40 rps peak

p99 0msavail 0.00%cost/mo at peak $0