How to practice lld and hld?

Practicing Low-Level Design (LLD) and High-Level Design (HLD) effectively involves a mix of understanding principles, solving problems, and iterating your designs. Here's how you can master both:

Practicing High-Level Design (HLD)

1. Learn Core Concepts

• System Requirements: Understand functional and non-functional requirements like scalability, reliability, and latency.
• Key Components:
  • Load Balancers: Distribute traffic across servers.
  • Databases: Learn SQL vs. NoSQL, sharding, and replication.
  • Caching: Speed up data retrieval using Redis or Memcached.
  • Messaging Queues: Handle asynchronous communication using Kafka or RabbitMQ.
• Design Principles: Understand CAP theorem, trade-offs, and architectural patterns like microservices, event-driven design, and monoliths.

2. Solve Common Problems

• Real-World Scenarios:
  • Design a URL shortener like TinyURL.
  • Architect a video streaming service like Netflix.
  • Build a social media feed like Instagram.
  • Create a ride-sharing system like Uber.

3. Follow a Structured Approach

1. Clarify requirements (functional and non-functional).
2. Outline high-level components and their interactions.
3. Explain trade-offs in your choices.
4. Consider edge cases and system failures.
5. Optimize for scalability and cost.

4. Use Dedicated Resources

• Courses:
  • Grokking System Design Fundamentals for beginners.
  • Grokking the System Design Interview for interview-focused prep.
  • Grokking the Advanced System Design Interview for advanced scenarios.
• Blogs:
  • System Design Primer.
  • 50 System Design Concepts Every Developer Must Know.

Practicing Low-Level Design (LLD)

1. Strengthen Object-Oriented Design (OOD) Skills

• Learn Core Principles:
  • SOLID principles: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion.
  • Design patterns: Singleton, Factory, Observer, Decorator, etc.

2. Practice Real-World Problems

• Common Scenarios:
  • Design a parking lot system.
  • Implement a library management system.
  • Model a food delivery app (e.g., UberEats).
  • Create a payment gateway system.

3. Follow a Step-by-Step Process

1. Clarify functional requirements.
2. Identify core objects and relationships.
3. Create class diagrams and UML diagrams.
4. Implement classes and methods, ensuring they follow OOD principles.
5. Test your implementation with edge cases.

4. Code Your Designs

• Use languages like Python, Java, or C++.
• Focus on writing clean, maintainable, and reusable code.

5. Use Practice Resources

• Books:
  • Head First Design Patterns by Eric Freeman.
  • Clean Code by Robert C. Martin.
• Courses:
  • Grokking Object-Oriented Design Interview.
  • Grokking Multithreading and Concurrency.

Tips for Both LLD and HLD

1. Mock Interviews: Participate in mock interviews to simulate real-world scenarios and get feedback.
   • DesignGurus.io Mock Interviews.
2. Collaborate: Discuss designs with peers or mentors to gain new perspectives.
3. Iterate: Revisit and refine your designs over time.
4. Stay Updated: Follow tech blogs from companies like Netflix, Google, and Uber to learn how real systems are built.

By consistently practicing these methods and leveraging the right resources, you can develop a strong foundation in both LLD and HLD, making you well-prepared for interviews and real-world design challenges.