Does Google do system design interview?

Yes, system design interviews are a significant part of Google’s hiring process, especially for mid-level to senior engineering positions. These interviews focus on your ability to architect and reason about large-scale, distributed systems—skills that are essential to building and maintaining the infrastructure behind products like Google Search, Gmail, and YouTube.

What to Expect in a Google System Design Interview

1. High-Level Architecture and Components:
You’ll start by discussing the overall structure of a system: how different services, databases, caches, load balancers, and queues interact. Google wants to see if you can outline a solution that can handle millions of users and large volumes of data efficiently.

2. Scalability and Performance:
A core theme is designing systems that can grow smoothly as the user base expands. You’ll delve into:

• Horizontal Scaling: Distributing load across multiple servers or regions.
• Data Partitioning (Sharding): Splitting data to manage high read/write volumes.
• Caching and CDNs: Reducing latency and database load.

3. Trade-Offs and Decision-Making:
Google emphasizes depth of reasoning. Interviewers will probe your design choices—why choose SQL or NoSQL? How do you balance consistency and availability? Show that you can:

• Recognize and explain the CAP theorem’s implications.
• Compare different approaches for load balancing or replication.
• Justify design decisions with clear trade-offs, like prioritizing low latency over absolute consistency depending on the use case.

4. Reliability and Fault Tolerance:
Systems must remain stable even when components fail. Be ready to discuss:

• Redundancy and Failover: Ensuring multiple instances can step in if one goes down.
• Replication: Keeping data synchronized across regions.
• Health Checks and Alerts: Detecting and responding to failures in real time.

5. Real-World Scenarios:
You may be asked to design a large-scale service similar to Google products or familiar platforms. Examples include:

• A URL Shortener: Handling massive read volume, quick lookups, and consistent hashing.
• A Video Streaming Service: Managing content delivery, buffering, and scaling to millions of concurrent viewers.
• A Global Map Service: Providing real-time updates, location queries, and efficient routing for billions of requests.

6. Clear Communication and Iteration:
The interviewer evaluates not just your design but also how you explain it. You should:

• Start with a high-level architecture before diving into details.
• Use diagrams and simple language to illustrate data flow and component interactions.
• Ask clarifying questions and incorporate feedback to refine your solution.