Problems / Design a product, easy
Design Pastebin from an empty canvas: create pastes and read them back by link, fast, at 1,500 requests a second.
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Request types to route: read (90%, read), create (10%, write). Budget: $6,500 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 ≥ 99.9%; p99 latency ≤ 100 ms (read); p99 latency ≤ 300 ms (create) |
| A paste goes viral | At 5 s a paste is linked from a big site: traffic triples for 8 s. | Success ≥ 99%; p99 latency ≤ 150 ms (read) |
| 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 ≤ 400 ms (read) |
| A server dies | At 4 s one server of the first app service on the request path dies for 10 s. | Success ≥ 99% |
| Budget: $6,500/month | The normal day's design must cost at most $6,500 a month. | Cost ≤ $6,500/month |