Data Storage & Management

Master the fundamentals of data storage systems and learn when to use each option in your system design interviews.

Quick Reference

When to Use DynamoDB

  • High-throughput requirements
  • Known access patterns
  • Serverless applications
  • Schema flexibility needs
  • Single-digit millisecond performance

When to Use Aurora

  • Complex queries with joins
  • Transactional consistency needed
  • Normalized schemas
  • Relational data models
  • Significant read scaling with replicas

When to Use ElastiCache

  • Frequently accessed data
  • Session storage
  • Leaderboards & rankings
  • API rate limiting
  • Reduce database load

System Design Interview Tips

When discussing data storage in your interview, always explain the rationale behind your choices:

Access Patterns

Explain how your data will be accessed: read-heavy vs write-heavy, query patterns, and frequency. This justifies your storage selection and demonstrates depth of understanding.

Consistency Requirements

Discuss CAP theorem trade-offs and whether your system needs strong consistency or can work with eventual consistency, explaining why based on business requirements.

Scaling Strategy

Address how your storage choices will scale with increased load, considering both vertical and horizontal scaling approaches appropriate to your selection.

Failure Handling

Explain how your data storage approach handles failures, including replication, backup strategies, and recovery procedures to meet availability requirements.