Requirements

Functional Requirements:

• Allow users to tweet messages up to 140 characters.
• Enable users to follow other users.
• Allow users to like tweets from other users.
• Display tweets from followed users in the home feed.
• Show top K popular tweets in the home feed based on likes and followers.

Non-Functional Requirements:

• List the key non-functional requirements (eg low latency, scalability, reliability, etc.)...
• At any time user should be able to tweet and see others tweet in his/her feed.
• Low Latency :- User should be able to tweet within 3-5 sec max, user should be able to refresh his/her home feed in 2-3 sec.
• Scalability:- The system must handle a high Read-to-Write ratio. We will implement Database Sharding by UserID to distribute data load and a Redis-based Fan-out service to pre-compute timelines. To handle "Celebrity" accounts, we will use a Hybrid Pull/Push model to prevent cache exhaustion. Horizontal scaling will be managed via a Load Balancer (Nginx/HAProxy) across stateless application servers.
• Reliability :- Even if any fault or any issues system should work consistently over a specific time.

API Design

Define the APIs expected from the system. This is your chance to analyze and define the read and write paths so that you can come up with the high-level design...

• POST - /user/tweet/createPost

Request :- {"content": "tweet details content", "contentId":uniqueNumber, "maxChar": 500}

Response: - {200}

• POST - /user/followOthers

Request:- {"toFollowUserName": "otherAccountUserName", "toFollowId":"followId"}

Response:- {200}

• POST - /user/likeTweet

Request:- {"tweetId": "otherUserContentId"}

Response:-200

• GET - /tweet/homeDisplay
• GET - /tweet/getTopKTweets

Request:- {"topKno": 10}

High-Level Design

Describe the overall system architecture. Identify the main components needed to solve the problem end-to-end. Use the diagramming tool to create a block diagram.

Detailed Component Design

Deep dive into 2-3 key components. Explain how they work, how they scale, discuss tradeoffs, capacity, and any relevant algorithms or data structures.