1. Functional Requirements (What Instagram Must Do)
User Account Management:
- Sign-up & Login: Users should be able to create an account via email, phone number, or social media accounts (like Facebook). They should also be able to log in securely.
- Profile Management: Users should have a personal profile where they can manage their photo, bio, username, and other personal details.
- Follow/Unfollow: Users should be able to follow other users and unfollow them as needed. This creates a feed of posts from the people they follow.
Photo and Video Sharing:
- Upload: Users must be able to upload photos and videos from their devices.
- Editing: Users should have the ability to apply filters, crop images, and add captions or tags to their photos or videos.
- Posts: Photos and videos should be posted either publicly or to a select group of followers.
Stories:
- Users must be able to create and share short-lived, 24-hour disappearing posts, called Stories, that can include photos, videos, text, or drawings.
- Users should be able to view others’ stories and interact with them.
Direct Messaging:
- Users should be able to send private messages to one another, including text, photos, videos, voice messages, and more.
- Group messaging should also be supported, allowing multiple people to interact in one conversation.
Feed and Explore Page:
- Home Feed: Users should see posts from the people they follow, and they should be able to like, comment, and share these posts.
- Explore Page: Users should be able to discover new content, users, and trends through personalized recommendations based on their activity.
Hashtags and Tagging:
- Users should be able to tag other users in posts, stories, and comments. This enables easy navigation and categorization of content.
- Hashtags should be available to categorize posts and make them discoverable to a larger audience.
Reels:
- Instagram should allow users to create and share short-form video content (reels) with added music, special effects, and editing tools.
E-commerce:
- Users and businesses should be able to showcase and sell products directly through Instagram, via Instagram Shopping, where users can purchase items tagged in photos, posts, and stories.
Live Streaming:
- Users should be able to broadcast live videos to their followers or the public.
- Real-time interaction with the audience should be possible through comments, reactions, and likes.
Notifications:
- Instagram must notify users of various events like new followers, likes, comments, mentions, and direct messages.
2. Non-Functional Requirements (How Instagram Must Perform)
Scalability:
- Instagram should be able to scale and support billions of users. The system must handle a large number of requests, especially during peak usage times (e.g., holidays, major events).
- This means that Instagram needs to distribute its resources across multiple data centers and use horizontal scaling to manage growing traffic.
High Availability and Reliability:
- Instagram needs to be available 24/7 with minimal downtime. This requires robust fault tolerance and redundancy to ensure that users can always access their accounts, even during failures.
- Load balancing and failover mechanisms are key to ensuring that the platform stays reliable even under heavy traffic conditions.
Low Latency:
- Instagram must deliver content quickly and with low latency. This is especially important for image and video content, where users expect instant loading.
- Techniques like content delivery networks (CDNs), caching, and edge servers help reduce load times and improve responsiveness.
Security and Privacy:
- Instagram must secure user data, including personal details, photos, videos, and communication.
- Strong encryption methods should be used for data storage and transmission, and the system must provide two-factor authentication (2FA) to prevent unauthorized access.
- Instagram must comply with privacy regulations such as GDPR (General Data Protection Regulation) and other data protection laws to ensure that user data is handled responsibly.
Data Consistency and Integrity:
- The system must ensure that user actions (like posting a photo, liking a post, or following someone) are consistent across all devices and platforms.
- Ensuring that data synchronization happens in real time, especially with features like stories, likes, and comments, is essential.
Performance:
- Instagram must handle millions (or billions) of requests per day efficiently. It should perform actions like liking a post, uploading a photo, or sending a message quickly, without causing delays.
- Data retrieval, especially for photos and videos, must be optimized for quick delivery.
User Engagement and Interactivity:
- Instagram needs to keep users engaged with features that encourage interaction, such as liking, commenting, sharing, and direct messaging.
- The platform also needs to encourage users to post frequently, either through personalized notifications, trending hashtags, or new feature adoption.
Content Moderation:
- Instagram needs to implement moderation tools to filter out harmful content such as hate speech, bullying, explicit content, and misinformation.
- AI algorithms and human moderators work together to ensure that inappropriate content is flagged and removed in real-time.
Internationalization:
- Instagram must support multiple languages and localization options so users from different countries can use the platform in their native languages.
- Currency and local customs should be taken into account, especially with features like Instagram Shopping.
Usability:
- Instagram must provide a user-friendly interface that is simple to navigate for both beginners and experienced users.
- The mobile app should be intuitive, with easy-to-use features for uploading content, interacting with others, and exploring new posts.
3. Goals of the Instagram System
Enhance User Experience:
- Instagram should offer an easy-to-use and visually appealing interface that makes it easy for users to share content, interact with others, and discover new media.
Maximize User Engagement:
- By providing features like Stories, Reels, and Direct Messaging, Instagram aims to encourage frequent interaction between users, keeping them engaged on the platform.
Provide Personalized Content:
- The Explore page and recommendations should be personalized for each user to ensure they see the most relevant and interesting content based on their interests and past activity.
Enable Content Discovery and Virality:
- Instagram’s system should allow content to be discovered and shared easily, helping to drive the viral spread of posts, videos, and hashtags. This is critical to Instagram’s growth and maintaining a large, active user base.
Support Creators and Brands:
- Instagram aims to provide tools that help influencers, content creators, and businesses build their brands and reach a larger audience. This includes features like sponsored posts, ads, and Instagram Shopping.
Ensure Security and Privacy:
- Protecting users’ data and maintaining privacy is a key goal for Instagram. It aims to keep users’ personal information secure while also providing ways for them to control who sees their posts and interact with them.
Enable Global Growth and Scalability:
- Instagram must handle an ever-growing number of users and content uploads across the world. The system needs to be scalable to accommodate growth while providing a high-performance experience for users everywhere.
Content Moderation and Safety:
- Ensuring that Instagram is a safe place for users is essential. The system should promote a positive and inclusive environment while preventing harmful behavior, such as cyberbullying, hate speech, and fake news.
Summary for Students:
- Functional Requirements: Instagram enables users to share photos, videos, stories, and more. It provides features like direct messaging, hashtag categorization, reels, and Instagram shopping to allow users to interact, engage, and discover content.
- Non-Functional Requirements: Instagram needs to perform well under heavy load, scale easily to billions of users, provide a secure environment, and ensure low latency.
- Goals: Instagram aims to keep users engaged with personalized content, encourage interaction, and provide a secure, user-friendly environment for sharing media and connecting with others.
