Does Google ask system design questions for L4?

Yes, Google does ask system design questions for L4 (Software Engineer) positions, but these questions are typically simpler and less complex than what is expected for more senior levels (e.g., L5 or L6). At L4, Google is evaluating your ability to understand the basics of system design, think critically about trade-offs, and demonstrate good decision-making in designing moderately complex systems.

What to Expect for L4 System Design Questions:

1. Basic System Components: You might be asked to design smaller, simplified versions of systems (e.g., designing a URL shortener or a basic message queue). The interviewer will want to see your understanding of essential components like databases, caching, and load balancing.

2. Scalability and Performance: You should be prepared to discuss basic strategies for scaling a system (e.g., vertical vs. horizontal scaling) and performance improvements like caching or database indexing.

3. Simplified Architecture: Unlike L5 and above, where the questions might involve designing large-scale, highly complex systems like "Design YouTube," L4 focuses more on showing an understanding of simple architectures and how different parts of the system interact.

4. Trade-offs: Demonstrating that you can weigh trade-offs between consistency, availability, and performance will be key. Even for a simpler system, it's important to justify your design decisions.

Common L4 System Design Question Topics:

• URL shortener: Design a system that shortens URLs and ensures that shortened links are unique and retrievable.
• Rate limiter: Build a system to limit how often a user can make API requests.
• Basic chat system: Design a chat system with 1-on-1 messaging (without complex group chats or notifications).
• Design a cache: How would you implement caching for an application with high read traffic?

Final Thoughts

While the system design expectations for L4 at Google are less intense than for senior positions, showing a solid understanding of the fundamentals is essential. Being able to discuss trade-offs, explain how the system can scale, and ensure fault tolerance are important aspects even for simpler designs.

To prepare for system design interviews at Google, you can use resources like Grokking the System Design Interview, which offers structured examples and practical advice on tackling system design questions.