Others·Data Scientist·Technical Phone Screen·Intermediate

Intermediate

Jul 2026

Summary

A coding-style question for a Data Scientist role, which felt a bit unexpected. Had to write a Bash snippet to find the largest file under a directory recursively. Not the kind of thing I practice regularly so it was a bit of a scramble.

Questions Asked (1)

Write a Bash function that recursively searches a given directory and returns the size in bytes of the largest regular file. If no regular files exist, return 0.

Algorithms & Data StructuresTechnical Trade-offs

Author's notes

I knew find and stat existed but blanked on the exact flags mid-interview.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements: the function should be recursive, handle regular files only, and return 0 if none exist. Then outline a solution using `find` with `-type f` and `-printf '%s\n'` to list sizes, piping to `sort -n` and `tail -1` to get the maximum. Finally, discuss edge cases like empty directories, permission issues, and performance considerations.

Pro tip: Mention that using `find` with `-printf` is more efficient and portable than parsing `ls` output, and that handling filenames with spaces or special characters is crucial. Also, note that returning 0 for no files is a design choice that should be confirmed with the interviewer.

1. Clarify requirements and constraints

Confirm that the function should be recursive, consider only regular files, and return 0 if none exist. Ask about handling symlinks, hidden files, and permission errors.

2. Choose the right tools

Select `find` for recursive traversal and file type filtering, and `stat` or `find -printf` for size extraction. Avoid parsing `ls` due to fragility with special characters.

3. Construct the pipeline

Use `find "$dir" -type f -printf '%s\n'` to list sizes, then `sort -n | tail -1` to get the maximum. Handle empty output by defaulting to 0.

4. Handle edge cases and errors

Consider empty directories, permission denied errors, and filenames with newlines. Use `2>/dev/null` to suppress errors or handle them explicitly.

5. Write and test the function

Implement the function in a script, test with sample directories, and verify correctness. Discuss potential performance improvements for large directories.

Key Points to Mention

Use of `find` with `-type f` to filter regular files only.
Using `-printf '%s\n'` for efficient size extraction without spawning extra processes.
Piping to `sort -n` and `tail -1` to find the maximum size.
Handling empty results by returning 0, e.g., using `|| echo 0` or a conditional.
Avoiding parsing `ls` due to issues with spaces, newlines, and special characters.
Considering performance: `find` is efficient, but for very large directories, alternatives like `du` or parallel processing might be discussed.

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