← Bitkernel Interview Insights

Bitkernel·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Apr 2026

Summary

Interviewed for a software engineer role at Bitkernel and got a file systems question that felt more like an OS exam than a coding screen. Not the most intense round but it tested whether you actually understood storage internals.

Questions Asked (1)

Q1

Which physical file structure is NOT suitable when a file system needs to support efficient random access to records? (Sequential/contiguous, Indexed, Linked, or Hash)

System DesignTechnical Trade-offsAlgorithms & Data Structures
Author's notes

The answer is linked files.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

First, clarify that the question asks for the least suitable structure for efficient random access. Then, evaluate each option based on its access pattern: sequential/contiguous and indexed allow direct access, hash allows O(1) average access, while linked requires traversal. Conclude that linked is the answer and explain why.

Pro tip: Mention that while linked allocation is poor for random access, it excels in sequential access and file growth, showing you understand trade-offs. Also, note that real systems often use hybrid approaches like indexed allocation with linked blocks.

1. Clarify the requirement

Restate that the goal is efficient random access to records, meaning we want to minimize disk I/O and seek time when accessing arbitrary records.

2. Analyze each structure

For each option, describe how random access is performed: sequential/contiguous uses direct offset calculation, indexed uses an index block, hash uses a hash function, and linked requires traversing pointers.

3. Compare access complexities

State the time complexity for random access: O(1) for contiguous and hash, O(1) or O(log n) for indexed, and O(n) for linked.

4. Identify the least suitable

Conclude that linked allocation is not suitable because it requires sequential traversal from the start to reach a specific record, making random access inefficient.

5. Discuss trade-offs

Briefly mention that linked allocation is beneficial for sequential access and file growth, but for random access, other structures are preferred.

Key Points to Mention

  • Random access requires direct computation of the record's location without scanning.
  • Contiguous allocation allows O(1) random access via block number calculation.
  • Indexed allocation uses an index block to map logical to physical blocks, enabling efficient random access.
  • Hash allocation uses a hash function to directly locate the block, giving average O(1) access.
  • Linked allocation stores records as a linked list of blocks, so random access requires O(n) traversal.
  • Trade-offs: linked allocation is good for sequential access and dynamic growth but poor for random access.

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