System design diagram

What is System Design?

  • Author : Sunil Ravulapalli
  • Date : 20th Oct, 2023


System design is a critical process that involves the assembly of various software infrastructure components to render software applications, websites, or mobile apps functional. This intricate task is pivotal for optimizing the performance and responsiveness of these digital products, catering to the demands of millions of users without delays. In this essay, we will explore the nuances of system design, from its fundamental components to the evolution of its paradigms.

Basic Components

At its core, a simplistic software system comprises a minimum of two key components: a server and a database. The server acts as the host for the application code, housing the business logic that powers the software. For anything beyond a static HTML page, data storage becomes a necessity, hence the need for a database.

However, the landscape of software design has evolved significantly over the past three decades. The modern era, characterized by unprecedented data traffic, necessitates system design to be optimized for high performance and minimal latency. Research underscores the adverse impact of sluggish websites on converting visitors into paying customers. Moreover, the popularity of websites results in exponential data growth, subsequently inflating storage costs. Consequently, cost optimization is a pivotal aspect of system design.

Advanced Components

System design incorporates a variety of components to ensure optimal functionality. These components include:

Server: The core of any software system, where code and business logic are hosted.

Database: Essential for storing data, particularly in dynamic applications.

Cache: Improves response times by storing frequently accessed data in memory.

Object Storage: Stores and manages unstructured data, such as images and videos.

Message Queues: Facilitate asynchronous communication and data processing.

Load Balancer: Distributes incoming network traffic across multiple servers to ensure reliability and efficiency.

Content Delivery Network (CDN): Enhances performance by serving content from geographically distributed servers.


Estimation is a critical aspect of system design, as it provides a rough estimate of the resources required to build a system. The resources required for a system are typically measured in terms of storage, bandwidth, and cache. These resources can be estimated when the software architects along with product managers can answer the following questions:

  • Number of writes per time period(ex: per month)
  • Number of reads per time period(ex: per month)
  • Size of each write

Tech Industry

System design plays a pivotal role in the tech industry, especially during interviews at prominent tech companies. It encompasses a wide range of challenges, from designing a simple URL shortening service to crafting complex systems akin to Netflix and Uber.

Designing an entire system is often an extensive, hours-long endeavor, one that even seasoned engineers approach with caution. Typically, engineers focus on a specific component or aspect of a larger system, but they must keep an eye on the broader context to prevent being blindsided by other requirements.


The approach to system design has witnessed a significant shift over the years. In the past, systems were predominantly designed as monoliths, with all components tightly integrated. However, contemporary methodologies, such as Service-Oriented Design (SOA) and microservices, have gained prominence. These approaches emphasize modular, loosely coupled components that enhance scalability, flexibility, and ease of maintenance.



In conclusion, system design is a multifaceted discipline essential for ensuring the efficiency and performance of software applications, websites, and mobile apps in today's digital landscape. It continues to evolve as the demands of modern technology and user expectations expand, emphasizing modularity, scalability, and adaptability to meet these ever-evolving challenges.

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