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

SeniorPrefer not to say
May 2026

Summary

System design coding round at Clay for a software engineer role. The whole thing was one extended problem about building a file system from scratch, and they really wanted you to think through the details, not just sketch something high level.

Questions Asked (1)

Q1

Design and implement a simplified file system called Workspace that supports folders and tables as node types, with a root node already present. Implement insert, list, delete, and move operations.

System DesignAlgorithms & Data StructuresTechnical Trade-offs
Author's notes

I started with a node class holding a name, type, parent pointer, and a map of children by name.

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AI HintsAI Generated

Suggested Approach

Clarify requirements and constraints first, then design a tree-based data structure with nodes representing folders and tables. Implement operations using recursive traversal or parent pointers, and discuss trade-offs between simplicity and efficiency.

Pro tip: Proactively discuss how you would handle edge cases like moving a folder into its own descendant or deleting non-empty folders, and mention potential optimizations like caching or indexing for large workspaces.

1. Clarify Requirements and Constraints

Ask about expected scale, concurrency needs, and whether operations should be atomic. Confirm node types and root initialization.

2. Design Data Structures

Choose a tree structure where each node has an ID, type, name, and children list (for folders) or data (for tables). Consider parent pointers for efficient moves.

3. Implement Core Operations

Write methods for insert (add child to folder), list (return children of a folder), delete (remove node and its subtree), and move (change parent, ensuring no cycles).

4. Analyze Complexity and Trade-offs

Discuss time/space complexity of each operation and alternatives (e.g., adjacency list vs. nested sets). Mention potential optimizations like lazy deletion or path compression.

5. Test and Validate

Walk through test cases: inserting into root, listing empty folder, deleting non-empty folder, moving folder into itself, and moving across different parents.

Key Points to Mention

  • Tree data structure with nodes having unique IDs and parent references
  • Handling of edge cases: moving a node into its own subtree, deleting non-empty folders
  • Time complexity: O(1) for insert if parent known, O(n) for delete/move in worst case
  • Trade-offs between recursive and iterative implementations
  • Potential concurrency issues if multiple operations occur simultaneously
  • Scalability considerations: indexing, caching, or using a database for persistence

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