Problems / Design a product, medium
Design Google Analytics from an empty canvas: page-view beacons from millions of sites at 4,000 a second, aggregated into dashboards within seconds.
Unlock it once for 15 credits; everything inside it is free (runs, changes, Submit, results, hints). Sign in with Google to start; new accounts get free credits.
Request types to route: hit (97%, write), dashboard (3%, read). Budget: $4,200 a month.
You start from an empty canvas. When you run the tests, each one simulates your design with its own traffic and failures:
| Test | What it does | Passes when |
|---|---|---|
| Normal day | The normal day: the traffic in the brief, nothing broken. | Success ≥ 99.8%; p99 latency ≤ 100 ms (hit); p99 latency ≤ 1.5 s (dashboard) |
| Black Friday | At 5 s every shop’s traffic triples for 8 s. | Success ≥ 99%; p99 latency ≤ 200 ms (hit); p99 latency ≤ 800 ms (dashboard) |
| DDoS attack | At 5 s 20,000 requests a second of flood traffic arrive for 10 s, alongside real users. | Success ≥ 99%; Attack blocked ≥ 95% |
| Cache flushed | At 5 s the cache on the request path is emptied, as after a restart or a bad deploy. | Success ≥ 99%; p99 latency ≤ 2.0 s (dashboard) |
| Budget: $4,200/month | The normal day's design must cost at most $4,200 a month. | Cost ≤ $4,200/month |