Build the backend systems that decide when and how Airbnb notifies guests and hosts

Design a notification system that avoids over-notifying a user across multiple channels.

Tell me about a production incident you debugged during on-call — what was the root cause and what did you change afterward?

Describe a backend service you built in Java/Kotlin/Scala end-to-end, including its failure modes.

How do you scope a project when requirements come from multiple partner product teams?

Tell me about mentoring a newer engineer through a code review or design discussion.

请用中文说明你如何在一个分布式系统里做流量削峰或消息去重。