What Is System Design

What Is System Design

Step 1 of 11

System design picks the shape of a system before the traffic picks one for you.

The Idea

System design is picking a shape for a system before the traffic picks one for you. You choose what the pieces are, how a request travels between them, and which limit — latency, cost, correctness, uptime — you protect when they collide. There is no correct answer, only a defended one.

Real-World Example

A ski resort is a system design problem on a mountain. Lift capacity, slope capacity and the café have to match: a faster gondola just moves the queue onto the piste. Before the first powder Saturday, the resort has already decided which of the three it lets suffer.

The Tradeoff

Every design pays for what it protects. A single server with one database beats a clever distributed one until it genuinely cannot cope, because each extra piece is another thing to deploy, monitor and fund. Design for the load you have plus the next order of magnitude, no further.

Your turn

Put the steps in the right order.

1. 1Sketch the components and trace how one request travels through them↑↓
2. 2Pin down what the system must do, and for how many users↑↓
3. 3Name the bottleneck that appears first and fix only that one↑↓
4. 4Agree the numbers: reads per second, writes per second, payload size↑↓

Check order

Mini quiz

1 / 3

System design is mostly about:

• APicking the fastest programming language
• BChoosing which constraints to protect when they conflict
• CWriting the shortest possible code
• DAdding as many services as you can