Cold start for new items

  • Choose
  • Model 15

Difficulty 4 of 5

Sellers list 50 new items/s. Item vectors come from clicks, so a new item has no vector and cannot appear in results. New items must be findable within 30 s. A listing must save within 200 ms at p99. Budget 800 USD/mo. Choose how new items reach the item index.

Play level

Options

  • Add new items at the nightly retrain
  • Embed the item text inside the listing request
  • Embed the item text from the change stream
One change feed keeps serving in stepTap or press Space to change the write paths

Goals and limits

p99 latency (Browse)
under 100 ms
p99 latency (Listings)
under 200 ms
Data age
under 30 s
Monthly cost
under 800 USD/mo
Traffic
2,000 req/s

Concepts

How players did

Player results load from the server.

All levels