Mock Interview Prompt 002: Notification Service

Prompt

Design a notification service that can send email, SMS, and push notifications.

Interviewer Notes

Listen for whether the candidate separates:

notification creation
user preferences
template rendering
provider dispatch
retries and failure handling

Optional Follow-Ups

User-level notification preferences
Rate limiting per user and per channel
Scheduled notifications
Delivery status tracking
Provider failover

What Strong Answers Usually Cover

asynchronous architecture with queues
multi-channel abstraction
retry and dead-letter handling
idempotency
provider integration boundaries
observability and delivery metrics