System Design Roadmap

This roadmap provides a comprehensive guide to mastering system design. It covers fundamental concepts, advanced topics, and practical examples, along with free resources to help you learn.


Table of Contents

  1. Introduction to System Design
  2. Key Concepts in System Design
  3. Designing Scalable Systems
  4. Database Design
  5. Caching Strategies
  6. Load Balancing
  7. Microservices Architecture
  8. Distributed Systems
  9. Messaging Systems
  10. API Design
  11. Security in System Design
  12. Real-World System Design Examples
  13. Practice and Resources

1. Introduction to System Design

What is System Design?

System design is the process of defining the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements.

Why is System Design Important?

  • Ensures scalability, reliability, and performance.
  • Helps in building robust and maintainable systems.
  • Prepares you for technical interviews at top tech companies.

Free Resources:


2. Key Concepts in System Design

Key Topics:

  • Requirements Gathering: Functional and non-functional requirements.
  • High-Level Design (HLD): Defining the overall system architecture.
  • Low-Level Design (LLD): Detailed design of individual components.
  • Trade-offs: Balancing between scalability, consistency, availability, and latency.

Free Resources:


3. Designing Scalable Systems

Key Topics:

  • Horizontal vs Vertical Scaling: Adding more machines vs upgrading existing ones.
  • Stateless vs Stateful Systems: Managing state in distributed systems.
  • Partitioning and Sharding: Splitting data across multiple databases.
  • Replication: Ensuring data availability and durability.

Free Resources:


4. Database Design

Key Topics:

  • Relational Databases: MySQL, PostgreSQL.
  • NoSQL Databases: MongoDB, Cassandra, DynamoDB.
  • Database Indexing: Improving query performance.
  • ACID vs BASE: Consistency models in databases.
  • Database Normalization: Reducing redundancy.

Free Resources:


5. Caching Strategies

Key Topics:

  • Cache Types: In-memory (Redis, Memcached), CDN caching.
  • Cache Eviction Policies: LRU, FIFO, LFU.
  • Cache Invalidation: Ensuring data consistency.
  • Write-Through vs Write-Back Caching.

Free Resources:


6. Load Balancing

Key Topics:

  • Load Balancer Types: Hardware vs Software (NGINX, HAProxy).
  • Algorithms: Round Robin, Least Connections, IP Hash.
  • Session Persistence: Sticky sessions.
  • Global Server Load Balancing (GSLB).

Free Resources:


7. Microservices Architecture

Key Topics:

  • Monolithic vs Microservices: Pros and cons.
  • Service Discovery: Consul, Eureka.
  • API Gateway: Routing and authentication.
  • Communication Protocols: REST, gRPC, GraphQL.

Free Resources:


8. Distributed Systems

Key Topics:

  • CAP Theorem: Consistency, Availability, Partition Tolerance.
  • Consensus Algorithms: Paxos, Raft.
  • Distributed Storage: HDFS, Amazon S3.
  • Distributed Messaging: Kafka, RabbitMQ.

Free Resources:


9. Messaging Systems

Key Topics:

  • Message Queues: RabbitMQ, ActiveMQ.
  • Pub-Sub Systems: Apache Kafka, Google Pub/Sub.
  • Message Delivery Semantics: At-most-once, At-least-once, Exactly-once.

Free Resources:


10. API Design

Key Topics:

  • RESTful APIs: Best practices.
  • GraphQL: Query language for APIs.
  • API Versioning: URI, Header, Query Parameter.
  • Rate Limiting: Throttling API requests.

Free Resources:


11. Security in System Design

Key Topics:

  • Authentication and Authorization: OAuth, JWT.
  • Encryption: SSL/TLS, AES.
  • Data Privacy: GDPR, CCPA.
  • DDoS Protection: Rate limiting, CAPTCHA.

Free Resources:


12. Real-World System Design Examples

Key Examples:

  • Design a URL Shortener (e.g., TinyURL).
  • Design a Social Media Platform (e.g., Twitter).
  • Design a Video Streaming Platform (e.g., Netflix).
  • Design a Payment System (e.g., Stripe).

Free Resources:


13. Practice and Resources

Practice Platforms:

Free Books:

YouTube Channels:


Conclusion

Mastering system design requires a combination of theoretical knowledge and practical experience. Use this roadmap to guide your learning journey and leverage the free resources provided to build a strong foundation.

System Design Interview Questions

This document contains a curated list of system design interview questions categorized by difficulty and topic. Use these questions to practice and prepare for your system design interviews.


Table of Contents

  1. Beginner-Level Questions
  2. Intermediate-Level Questions
  3. Advanced-Level Questions
  4. Real-World System Design Questions
  5. Behavioral Questions for System Design Interviews

1. Beginner-Level Questions

These questions are designed to test your understanding of basic system design concepts.

Questions:

  1. What is the difference between horizontal and vertical scaling?
  2. Explain the CAP theorem and its implications in distributed systems.
  3. What is the purpose of a load balancer, and how does it work?
  4. Describe the difference between SQL and NoSQL databases.
  5. What is caching, and why is it important in system design?
  6. How does a CDN (Content Delivery Network) work?
  7. What is the difference between monolithic and microservices architecture?
  8. Explain the concept of sharding in databases.
  9. What is the role of an API Gateway in microservices?
  10. How do you ensure data consistency in a distributed system?

2. Intermediate-Level Questions

These questions require a deeper understanding of system design principles and trade-offs.

Questions:

  1. Design a URL shortening service like TinyURL.
  2. How would you design a rate-limiting system for an API?
  3. Design a notification system for a mobile app.
  4. Explain how you would design a distributed logging system.
  5. Design a system for handling file uploads and downloads (e.g., Google Drive).
  6. How would you design a chat application like WhatsApp?
  7. Design a recommendation system for an e-commerce platform.
  8. How would you implement a leaderboard for a multiplayer game?
  9. Design a system for real-time analytics (e.g., tracking website clicks).
  10. How would you design a distributed task scheduler?

3. Advanced-Level Questions

These questions test your ability to design complex, scalable, and fault-tolerant systems.

Questions:

  1. Design a global video streaming platform like Netflix.
  2. How would you design a social media platform like Twitter?
  3. Design a payment processing system like Stripe.
  4. How would you design a search engine like Google?
  5. Design a distributed file storage system like Dropbox.
  6. How would you design a ride-sharing service like Uber?
  7. Design a real-time collaborative document editing system like Google Docs.
  8. How would you design a distributed cache system like Redis?
  9. Design a system for handling stock market data in real-time.
  10. How would you design a distributed messaging system like Kafka?

4. Real-World System Design Questions

These questions are inspired by real-world systems and are commonly asked in interviews.

Questions:

  1. Design a system for handling spikes in traffic (e.g., during a product launch).
  2. How would you design a system for handling user authentication and authorization?
  3. Design a system for managing user sessions in a distributed environment.
  4. How would you design a system for handling large-scale data processing (e.g., MapReduce)?
  5. Design a system for handling real-time notifications for millions of users.
  6. How would you design a system for handling geolocation-based queries (e.g., nearby restaurants)?
  7. Design a system for handling version control (e.g., Git).
  8. How would you design a system for handling ad serving (e.g., Google Ads)?
  9. Design a system for handling real-time multiplayer game state synchronization.
  10. How would you design a system for handling distributed locks?

5. Behavioral Questions for System Design Interviews

These questions assess your problem-solving approach and communication skills during system design interviews.

Questions:

  1. Walk me through your thought process for designing a scalable system.
  2. How do you handle trade-offs between consistency, availability, and partition tolerance?
  3. Describe a time when you had to design a system under tight constraints.
  4. How do you prioritize features when designing a system?
  5. Explain how you would handle a system failure or outage.
  6. How do you ensure that your system design is maintainable and extensible?
  7. Describe a time when you had to optimize a system for performance.
  8. How do you approach designing systems for high availability?
  9. Explain how you would handle security concerns in your system design.
  10. How do you communicate your design decisions to non-technical stakeholders?

Conclusion

Use these questions to practice and refine your system design skills. Focus on understanding the trade-offs, scalability, and reliability aspects of each problem. Good luck with your interviews! 🚀