About Hot Path

Hot Path is five browser games about systems developers already know about: CPU pipelines, OS scheduling, distributed consensus, internet routing and cloud billing. Each one is a working model you can watch, tune and break.

The numbers are illustrative

This is the most important thing on this page. Every latency, price, timeout and cost in these games is an approximation chosen to teach a mechanism. They are drawn from published sources — textbooks, papers, public pricing pages, public post-mortems — and each sim's NOTES document lists what was used and what was simplified.

None of them is a measurement. A cache miss in Stall is not a measurement of any real chip. A price in Egress is not a quote from any real cloud. If you need real numbers, measure the real system.

Fictional actors, real incidents

Every autonomous system, cloud provider, company and product inside the games is fictional. Some scenarios are inspired by real, publicly documented incidents, and where they are, the scenario says so and links to the public post-mortem. The lesson is real; the cast is not.

How the simulations work

Each model is pure TypeScript with no access to the clock or to a random number generator it does not own. It runs in a Web Worker at a fixed timestep while the main thread draws. A run is a seed plus a log of your inputs, which is why a share link can replay a run exactly rather than approximately.

Every model also ships a set of invariants — statements that must be true of any valid state. They are checked in tests against randomized chaos runs, and you can turn them on while you play. If one ever fires during your run, that is a bug in the model, and the run is worth sharing.

Privacy

There are no accounts, no trackers and no analytics by default. Progress lives in your browser's local storage and can be exported or deleted from the settings panel at any time.

No dark patterns

No streaks, no notifications, no fake urgency, nothing that nags. The bill shock in Egress is a mechanic inside a game about bill shock — it is not a technique aimed at you.