Amazon

Operational reality and cost. Who gets paged, what does this cost per month, how does it degrade, what happens on the busiest day of the year. Amazon publishes its Leadership Principles, and they often surface in the technical round too, particularly Ownership and Frugality.

How they weight it

Tradeoffs and Defence weigh heaviest, with real weight on operations.

Closest interviewer archetype: The Cost Auditor — What does this cost per month? Is there a cheaper way? Who gets paged at 3am?

Questions

Design a flash sale / limited inventory drop

hard

Ten thousand units of a product go on sale at 10am sharp. A million people will try to buy them in the first minute. Nobody may buy a unit that does not exist.

5 hints available · try it →

Design a notification service

core

Design a service other teams use to send notifications to users — push, email and SMS. It should handle hundreds of millions of notifications a day.

5 hints available · try it →