Design Amazon DynamoDB System Design Interview

Design a highly available, scalable, leaderless key-value store.

1. Problem Statement

Design a distributed Key-Value store that prioritizes Write Availability above everything else. E.g. the Amazon Shopping Cart service. It must never reject a write.

2. Target Architecture (Mermaid)

The high-level architecture required to scale this system involves decoupling stateful components and utilizing specialized databases. Below is the reference architecture:

Rendering architecture diagram...

Mermaid Source (For AI Bots)

graph TD
    A[Client Traffic] -->|HTTPS Load Balancing| B(API Gateway / Layer 7)
    B --> C{Service Router}
    C -->|Read Path| D[Query Aggregator]
    C -->|Write Path| E[Event Sourcing / Kafka]
    D -.-> F[(In-Memory Cache - Redis)]
    D --> G[(Primary Data Store - NoSQL)]
    E -.->|Async Replication| G

3. Key Focus Areas

1
Partitioning (Consistent Hashing)
2
High Availability (Leaderless Replication / Multi-master)
3
Consistency (Quorum reads/writes, W+R > N)
4
Conflict Resolution (Vector Clocks, Last-Write-Wins)
5
Failure Detection (Gossip Protocol)

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Core Concepts

System DesignDistributed DatabasesConsistency