Introduction to System Design

Systems Design is about planning how a system works, including its structure, interfaces, and data, to meet specific needs. When creating a software application, we want to make sure it runs well, is reliable, and can grow as needed.

Our Project: "FriendShare"

Suppose we are building a social media mobile app called "FriendShare." First, we need to outline some minimal requirements expected of the app:

1. Users can post text, images, and videos.

Based on these requirements, we can now define the following components for the system:

1. Mobile Applications (Client-side):
   • Android app
   • iOS app These apps should be easy to use, fast, and visually appealing for a great user experience.
2. Backend Service (Server-side): This is the main part that handles user requests, stores data, and keeps everything running smoothly. We can use programming languages like Python or Java based on what we need.
3. Database (Server-side): This stores all important data, like user profiles and posts, safely and efficiently.

How These Components Work Together

1. A user uploads a photo using their mobile app.
2. The Backend Service gets this request, processes it, and saves the photo and its details in the Database.
3. When another user opens the app, the Backend retrieves the stored information and sends it to their device. This setup is called "client-server architecture." The client (mobile app) talks to the backend (server), which manages everything and communicates with the database to store and get data.

This organized approach has many benefits:

• Separation of Concerns: The front-end (mobile apps) focuses on user interaction, while the backend manages data and logic.
• Scalability: Each part can grow and change independently as more users join or new features are added.
• Flexibility: Changes to one part (like backend updates) won’t disrupt the whole system, ensuring it remains reliable.

Exercise

Let’s practice! In the diagram provided, you’ll see an Android app and a backend service. Your task is to add an iOS app to complete the system design for FriendShare. This exercise will help you understand how different parts work together. Note that thereSystem design is about creating solutions that are efficient, scalable, and reliable. There are many ways to solve a problem, and exploring these options will help you learn about the trade-offs involved. Let’s get started!