System Design Cheatsheet for FAANG Interviews Circulates
A popular cheatsheet is making the rounds among engineers preparing for interviews, listing 35 real system design questions reportedly asked at Google, Meta, and Amazon. The questions cover high-scale architecture for apps like Dropbox and Uber, signaling the continued importance of distributed systems knowledge for SDE2+ roles.
System design interviews for SDE2+ roles at major tech companies are typically 45-60 minute, open-ended discussions. Candidates are often asked to design a large-scale system like a file-sharing service or a ride-hailing app. The goal is to assess a candidate's ability to handle ambiguity, clarify requirements, and make reasoned trade-offs in their design. These interviews focus on a candidate's understanding of distributed systems, which are essential for building scalable, reliable, and high-performance applications. Interviewers evaluate knowledge of concepts like load balancing, caching, databases, and message queues. The ability to discuss trade-offs, such as those between consistency and availability, is a key indicator of an engineer's maturity. For a problem like designing Dropbox, interviewers look for a discussion of both functional requirements, such as file upload and synchronization, and non-functional requirements like durability and low latency. A strong candidate would break the problem down into components like a client application, a metadata database, and a block storage service. Key considerations include how to handle large files, data synchronization across multiple devices, and offline support. When designing a system like Uber, the focus shifts to real-time data processing and high-throughput services. Interviewers expect candidates to discuss components for rider and driver matching, location tracking, and dynamic pricing. Important architectural patterns to consider include geospatial indexing, publish-subscribe messaging systems, and event-driven architectures. Beyond specific technical choices, the interview is a test of communication and structured problem-solving. A common approach is to first clarify the system's requirements and constraints, then sketch a high-level architecture, and finally, deep-dive into specific components. Using diagrams to illustrate the data flow and system components is highly recommended. The popularity of resources like this cheatsheet highlights a shift in the industry towards evaluating practical problem-solving and architectural skills over purely algorithmic knowledge. For SDE2 and more senior roles, demonstrating the ability to design complex, real-world systems is crucial for success.
