System-Design-Question

Added prompts for technical interview & skill gap coach and Explain Code / System Design Clearly

Category: system_design Date: 2026-02-20

Added Prompts for Technical Interview & Skill Gap Coach:

As a principal FAANG system design interviewer, I’d like to add the following prompts to assess a candidate’s skills:

  1. System Design for a given Problem Statement: Ask the candidate to design a system for a specific problem statement, and evaluate their ability to identify key requirements, high-level architecture, database design, and scaling strategy.
  2. Trade-off Analysis: Present a scenario where multiple design choices are available, and ask the candidate to analyze the trade-offs and choose the best approach.
  3. Code Review and Refactoring: Provide a sample code snippet and ask the candidate to review and refactor it to improve performance, scalability, and maintainability.
  4. System Design for a Real-World Problem: Ask the candidate to design a system for a real-world problem, such as a social media platform or an e-commerce site.

Skill Gap Coach Prompts:

To identify skill gaps, I’d like to add the following prompts:

  1. System Design for a Domain: Ask the candidate to design a system for a specific domain (e.g., finance, healthcare, or e-commerce).
  2. Database Design for a Large Dataset: Provide a sample dataset and ask the candidate to design a database schema to handle large-scale data.
  3. Scalability and Performance Optimization: Ask the candidate to identify bottlenecks in a system and suggest optimizations to improve scalability and performance.

Explain Code / System Design Clearly:

To evaluate a candidate’s ability to explain code and system design clearly, I’d like to ask the following prompts:

  1. Code Review and Explanation: Provide a sample code snippet and ask the candidate to explain the code’s functionality, design decisions, and trade-offs.
  2. System Design Walkthrough: Ask the candidate to explain the high-level architecture, database design, and scaling strategy of a system.
  3. Complexity Reduction: Provide a complex system design and ask the candidate to simplify it by identifying key components and explaining their interactions.

First Principle of System Design:

The first principle of system design is to Separate Concerns. This principle states that a system should be designed to separate different concerns, such as business logic, data storage, and scalability, to improve maintainability, scalability, and performance.

Example System Design Discussion:

Let’s consider a real-world problem statement: Design a system for a social media platform with the following requirements:

  1. Functional Requirements:
    • Users can create accounts and post updates.
    • Users can follow other users to see their updates.
    • Users can like and comment on updates.
  2. Non-Functional Requirements:
    • The system should handle 10,000 concurrent users.
    • The system should store 100 million updates.
    • The system should handle 1000 updates per second.

High-Level Architecture:

The high-level architecture of the system would involve the following components:

  1. API Gateway: Handles incoming requests from users.
  2. User Service: Manages user accounts and follows.
  3. Content Service: Stores and retrieves updates.
  4. Notification Service: Sends notifications to users when they are followed or liked.

Database Design:

The database design would involve the following tables:

  1. Users: stores user information (e.g., username, password).
  2. Follows: stores follow relationships between users.
  3. Updates: stores updates (e.g., text, image).
  4. Likes: stores likes on updates.
  5. Comments: stores comments on updates.

Scaling Strategy:

To handle 10,000 concurrent users, we would implement the following scaling strategy:

  1. Horizontal Partitioning: Divide the user base into smaller partitions based on geography or user behavior.
  2. Load Balancing: Distribute incoming requests across multiple API gateways.
  3. Caching: Cache frequently accessed data to reduce database queries.
  4. Sharding: Shard the database across multiple servers to handle large-scale data.

Bottlenecks:

The bottlenecks in the system would be:

  1. Database queries: Handling 1000 updates per second would put a high load on the database.
  2. API gateway: Handling 10,000 concurrent users would require a high-performance API gateway.
  3. Notification service: Sending notifications to users would require a scalable notification service.

Trade-offs:

The trade-offs in the system would be:

  1. Data consistency: Sacrificing data consistency for high availability and performance.
  2. Scalability: Sacrificing scalability for data consistency and performance.
  3. Complexity: Sacrificing complexity for maintainability and scalability.

Note: This is a simplified example, and a real-world system design would require a more detailed analysis of the requirements, architecture, database design, and scaling strategy.

This site is open source. Improve this page.