Introduction

What is System Design?

System Design is the process of defining the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. It’s a critical phase in software development that ensures the system will be scalable, reliable, maintainable, and efficient.

1. It involves making high-level design decisions about:

2. How different parts of the system will interact

3. What technologies will be used

4. How to handle data storage, communication, and scaling

5. How to ensure fault tolerance, performance, and security

Types of System Design

System Design is generally classified into two broad categories:

1. High-Level Design (HLD) – Architectural Design Focuses on overall system architecture

   • Breaks the system into modules/components

   • Defines how these components interact

   • Examples:

     • Microservices vs. Monolith

     • API Gateway placement

     • Database selection and partitioning

2. Low-Level Design (LLD) – Detailed Design

   • Focuses on the internal design of components/modules

   • Includes class diagrams, function definitions, database schemas

   • More implementation-focused

Other Classifications Based on Use Case

You can also look at system design types based on the nature of the system being built:

Type	Description
Monolithic Design	A single-tiered architecture where all components are tightly coupled
Microservices Design	The system is broken into small, independently deployable services
Distributed Systems	Designed to run across multiple machines, often in different locations
Real-time Systems	Systems where response time is critical (e.g., trading platforms, IoT)
Event-driven Design	System reacts to events (e.g., Kafka-based pipelines)
Serverless Design	Logic runs in functions on cloud platforms (e.g., AWS Lambda)
Scalable Systems	Designed to handle growth in users or data (e.g., load balancing, sharding)
Fault-tolerant Systems	Built to recover gracefully from failures (e.g., retries, circuit breakers)

note

📌 System Design is the process of defining the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements.

📌 It includes high-level design (overall structure and technology choices) and low-level design (detailed implementation and schemas).

📌 Based on the use case, different design patterns like microservices, distributed systems, or event-driven architectures are applied to meet performance, scalability, and fault-tolerance needs.