10 System Design Concepts in Plain English:

1 Scalability

↳ Handle extra load without affecting performance.

2 Load Balancer

↳ Route requests to free servers to avoid overload.

3 Cache

↳ Keep hot data nearby for quick access.

4 Sharding

↳ Split the data into smaller parts so that many servers share the load.

5 Replication

↳ Keep data copies so the system is available during failures.

6 Message Queue

↳ Store and serve messages between services reliably.

7 CDN

↳ Edge servers around the world for fast delivery and caching.

8 Rate Limiter

↳ Controlling the number of requests a user can make in a time window.

9 Monitoring

↳ Checking system metrics, logs, and alerts to find problems early.

10 Failover

↳ Automatic switching to the backup system on failure to avoid service problems.

(That’s 80% of the concepts you need to know.)

What else would you add?