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Amazon·Software Engineer·Onsite - System Design / Architecture·Senior

Senior
May 2026

Summary

Amazon SWE interview with a system design question about building a file system. Not a lot of context to go on but it was clearly a design round.

Questions Asked (1)

Q1

Design a file system from scratch.

System DesignTechnical Trade-offsData Modeling
Author's notes

This one has a lot of surface area and I'm not sure I scoped it well.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and constraints, then outline a high-level design covering core components like namespace, metadata, and data storage. Dive into key operations (create, read, write, delete) and discuss trade-offs around consistency, scalability, and durability, aligning with Amazon's leadership principles.

Pro tip: Proactively discuss how your design handles failure scenarios and scales to millions of users, as Amazon values operational excellence and customer obsession. Also, relate decisions to real-world systems like S3 or DynamoDB to show practical insight.

1. Clarify Requirements

Ask questions to understand scope: single-node vs distributed, expected scale, consistency needs, and features like permissions or versioning. This ensures you design the right system.

2. High-Level Design

Sketch the architecture: separate metadata (namespace, permissions) from data storage, and define APIs for file operations. Consider using a tree structure for directories and unique IDs for files.

3. Deep Dive into Components

Detail metadata storage (e.g., database choice), data storage (e.g., block storage, object storage), and how operations like read/write work. Discuss caching, indexing, and partitioning for scalability.

4. Address Trade-offs and Scalability

Discuss consistency models (strong vs eventual), replication for durability, and sharding for scale. Explain how to handle concurrent access and failures.

5. Summarize and Evaluate

Recap key decisions, mention potential bottlenecks, and suggest improvements. Tie back to Amazon's principles like customer obsession and ownership.

Key Points to Mention

  • Namespace and metadata management (e.g., hierarchical directories, file attributes)
  • Data storage strategies (block vs object storage, chunking, replication)
  • Consistency and durability trade-offs (CAP theorem, ACID vs BASE)
  • Scalability techniques (sharding, partitioning, load balancing)
  • Fault tolerance and recovery (replication, erasure coding, backups)
  • Security and permissions (access control lists, authentication)

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.