Backend for frontend

  • Build
  • Pixel 05

Difficulty 3 of 5

1,000 phones in a stadium share a 120 Mbps cell and refresh the match screen once a second. Each screen calls four services and gets 20 KB from each. The cell is full. Bring p99 under 140 ms. Budget: 46 USD/month, at most 2 new parts.

Play level

HTTP/2HTTP/2HTTP/2HTTP/2Live browse…1,000 req/sNode API2 vCPU · 2 GBNode API2 vCPU · 2 GBNode API2 vCPU · 2 GBNode API2 vCPU · 2 GB
HTTP/2HTTP/2HTTP/2HTTP/2Live browse…1,000 req/sNode APINode APINode APINode API
The board at the start of the level
A page waits for its slowest callDrag or use arrow keys to change the calls per page

Calls per page: 20 · 18% of pages wait 2.0 s

Goals and limits

p99 latency
under 140 ms
Error rate
under 0.1%
Monthly cost
under 46 USD/mo
Parts you can add
App backend
Part limit
2
Traffic
1,000 req/s

Concepts

How players did

Player results load from the server.

All levels