.NET Architecture & System Design Interview Question #6

What is scalability?

Architecture Fundamentals, Scalability, Availability & Performance Junior Beginner

Quick Interview Answer

Scalability is a system's ability to handle increased workload by adding or improving resources while maintaining acceptable service levels.

Detailed Explanation

Scalability is a system's ability to handle increased workload by adding or improving resources while maintaining acceptable service levels.

A scalable design considers which resource becomes constrained as load grows. Scaling may involve application instances, databases, caches, queues, storage, or external dependencies rather than only adding web servers.

Code Example

Load increases
     |
Identify bottleneck
     |
Scale application / database /
cache / queue / storage