The problem
System design is taught with boxes and arrows. You never see what happens when 400 cache keys expire at once, or a service hangs.
How it works
- 01Pick an idea
- 02Move the sliders
- 03Watch it happen
- 04Read the verdict
What was hard
- Each one is a real simulation stepped in small time slices — Poisson traffic for the rate limiter, a thread pool for the circuit breaker.
- Every simulator explains what you are seeing in one plain sentence that changes with the numbers.
The result
Four simulators that run smoothly on a phone.