System Design: From Business Requirements to Scalable Architecture
System design is often presented as a collection of components: APIs, databases, caches, message queues, load balancers, and microservices. But real system design is not about knowing a list of technologies. It is about understanding requirements, constraints, trade-offs, and failure scenarios and then designing a system that can evolve as those requirements change. A well-designed system should not only work today. It should be able to handle increasing traffic, growing data volumes, component failures, security requirements, operational complexity, and future business needs. 1. Start With the Requirements Before choosing any technology, understand what the system actually needs to accomplish. There are two broad categories of requirements. Functional Requirements These describe what the system should do. For example, consider a food delivery platform: Customers should be able to search for restaurants. Customers should be able to place orders. Restaurants should receive orders. Deli...