Question 1

Is Mutexmachine free?

Accepted Answer

Yes. Mutexmachine is free to use in the browser.

Question 2

Do I need an account?

Accepted Answer

No. Progress and preferences are stored locally in your browser.

Question 3

Does it work on mobile?

Accepted Answer

Yes. The simulator has responsive layouts for mobile screens, though complex architecture work is easier on a larger display.

Question 4

Is this good for system design interviews?

Accepted Answer

Yes. It helps practice backend tradeoffs, bottleneck diagnosis, incident response, and explaining post-mortems.