How do I approach System Design interview questions?

System Design questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master system design interviews.

What difficulty level is this interview question?

This is a hard difficulty System Design question, commonly asked during Onsite rounds at Airbnb.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Airbnb during technical interviews.

Design scalable notification system | Airbnb Interview Question

Quick Overview

This question evaluates a candidate's ability to design scalable, low-latency, multi-channel notification systems, testing competencies in distributed systems architecture, reliability and fault tolerance, data modeling, API design, capacity planning, message routing, monitoring, and cost trade-offs.

System Design: Low-Latency, Multi-Channel Notification Platform

You are asked to design a scalable, reliable notification system that can send messages to millions of users with low latency across multiple channels (email, SMS, push).

Assume a large, consumer-facing product operating globally with both transactional (real-time) and bulk/marketing use cases.

Cover the following:

Requirements Gathering
- Functional, non-functional, traffic assumptions, SLAs/latency targets, compliance.
High-Level Architecture
- Core components and data flow for real-time, scheduled, and bulk sends.
Data Model
- Key entities (templates, preferences, messages, attempts, providers, etc.).
API Design
- Producer APIs, admin APIs, idempotency, status callbacks/webhooks.
Message Prioritization
- Priority levels, queueing, fairness, rate limits, quotas.
Deduplication
- Idempotency keys, content-based dedup, time windows.
Retries and Failure Handling
- Backoff, dead-letter queues, poison-pill handling, fallback channels, circuit breaking.
Scaling Strategies
- Partitioning, horizontal scaling, multi-region, autoscaling triggers.
Monitoring and Alerting
- SLIs/SLOs, metrics, logs, traces, runbooks.
Cost Considerations

Unit economics by channel, routing, batching, budgets, frequency caps.

State reasonable assumptions where needed and explain trade-offs.

Quick Overview

System Design: Low-Latency, Multi-Channel Notification Platform

You are asked to design a scalable, reliable notification system that can send messages to millions of users with low latency across multiple channels (email, SMS, push).

Assume a large, consumer-facing product operating globally with both transactional (real-time) and bulk/marketing use cases.

Cover the following:

Requirements Gathering

Functional, non-functional, traffic assumptions, SLAs/latency targets, compliance.

High-Level Architecture

Core components and data flow for real-time, scheduled, and bulk sends.

Data Model

Key entities (templates, preferences, messages, attempts, providers, etc.).

API Design

Producer APIs, admin APIs, idempotency, status callbacks/webhooks.

Message Prioritization

Priority levels, queueing, fairness, rate limits, quotas.

Deduplication

Idempotency keys, content-based dedup, time windows.

Retries and Failure Handling

Backoff, dead-letter queues, poison-pill handling, fallback channels, circuit breaking.

Scaling Strategies

Partitioning, horizontal scaling, multi-region, autoscaling triggers.

Monitoring and Alerting

SLIs/SLOs, metrics, logs, traces, runbooks.

Cost Considerations

Unit economics by channel, routing, batching, budgets, frequency caps.

State reasonable assumptions where needed and explain trade-offs.

Design scalable notification system

Quick Overview

System Design: Low-Latency, Multi-Channel Notification Platform

Solution

Comments (0)

Design scalable notification system

Quick Overview

System Design: Low-Latency, Multi-Channel Notification Platform

Solution

Comments (0)