Qu’est-ce que la conception de systèmes ?

How are giants like Instagram or Netflix actually built? Not just code — it is system design: defining the architecture, components, and data that meet real requirements.

Building without a blueprint gets you walls that do not connect. System design is that blueprint — it surfaces problems early and leads to robust, scalable apps.

Coding is the how of one feature; system design is the what and why of the whole thing. It is the big picture before you dive into details.

The system is everything: your software components and APIs, the hardware they run on, the data they store, and the users interacting with it all.

Good design chases four qualities: scalability, reliability, maintainability, and efficiency. Every decision you make trades against these.

Design starts with requirements — what users and the business actually need. You then translate those into a high-level plan of components and how they connect.

System design means thinking in abstractions: start with big blocks like User Service or Database, then break them into smaller parts as you go deeper.

Design is never one-and-done — it is iterative. You design, gather feedback, and refine as requirements shift and new tech appears.

Based on what you've learned, which statement best describes the primary focus of System Design?

You took your first step into system design: the blueprint for robust software that plans the what and why before the how, aiming for scale and reliability.