This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Design notification and project architecture states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
##### Question
Design a scalable Notification System that supports real-time and scheduled messages across multiple channels (email, push, SMS). Detail components, data flow, storage, failure handling, and scaling strategy. Then, draw and explain the end-to-end architecture of one of your past projects, covering services, databases, communication patterns, and answer deep domain-specific follow-up questions.
Quick Answer: This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Design notification and project architecture states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System Design: Multi-Channel Notification Platform
Design a scalable Notification System that supports real-time and scheduled messages across multiple channels (email, push, SMS). Assume this is for a high-traffic consumer platform with millions of users and mission-critical notifications.
Assumptions (you may adjust if you state them explicitly):
Traffic: up to 50k notifications/second at peak, 1B/day worst case during major events.
Channels: email, mobile push, SMS; multiple third-party providers per channel for redundancy.
Scheduling: immediate and future delivery (seconds to 30 days ahead), with cancel/reschedule.
Global audience with time zones, quiet hours, user preferences, and regulatory constraints.
Deliverables
Components: Enumerate core services and infra.
Data flow: Real-time and scheduled paths end-to-end.
Storage: Schemas/data models for templates, preferences, schedules, logs, idempotency.