Top 10 System Design Concepts Every Developer Must Know

System design interviews are notoriously ambiguous. Unlike DSA, there is no single "correct" answer, only trade-offs. Here are the core concepts you must understand.

1. Load Balancing

Distributes incoming network traffic across multiple servers to ensure no single server bears too much demand, improving responsiveness and availability.

2. Caching

Storing copies of frequently accessed data in a temporary storage location (like Redis or Memcached) so future requests can be served faster.

3. Database Sharding

A type of database partitioning that separates very large databases into smaller, faster, more easily managed parts called data shards.

4. Message Queues

Tools like Kafka or RabbitMQ that enable asynchronous communication between microservices, decoupling heavy processing from the main application flow.

5. Consistent Hashing

A hashing strategy used in distributed systems (like distributed caches) that minimizes the reorganization of keys when nodes are added or removed.