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IBM·Software Engineer·Online Assessment (OA)·Junior

JuniorPending
Jun 2026

Summary

IBM intern OA as a rising sophomore. Two coding questions, one doable and one absolutely brutal. The second question involved navigating a large existing codebase to fix bugs, which was a nightmare for someone with zero real dev experience.

Questions Asked (2)

Q1

Solve a standard algorithmic coding problem (LeetCode-style, moderate difficulty).

Algorithms & Data Structures
Author's notes

Passed all the test cases on this one so at least something went right.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem constraints and edge cases, then discuss a brute-force solution before optimizing with appropriate data structures or algorithms. Walk through your thought process, write clean code, and test with examples to ensure correctness.

Pro tip: Always verbalize your reasoning and trade-offs; interviewers value clear communication and problem-solving skills over silent coding. If stuck, ask for hints or simplify the problem to make progress.

1. Understand and Clarify

Restate the problem in your own words, ask clarifying questions about input/output, constraints, and edge cases. Confirm assumptions with the interviewer.

2. Explore Approaches

Discuss a brute-force solution first, then analyze its time and space complexity. Brainstorm optimizations using appropriate data structures or algorithmic paradigms.

3. Plan and Code

Outline your chosen approach step-by-step, then write clean, modular code. Use meaningful variable names and handle edge cases explicitly.

4. Test and Debug

Walk through your code with a few test cases, including edge cases. Identify and fix any bugs or logical errors.

5. Analyze and Optimize

State the final time and space complexity. Discuss potential improvements or alternative solutions if time permits.

Key Points to Mention

  • Time and space complexity analysis for each approach
  • Edge cases and constraints (e.g., empty input, large values, duplicates)
  • Choice of data structures (e.g., hash maps, heaps, trees) and why
  • Trade-offs between different solutions (e.g., readability vs. performance)
  • Testing methodology and validation with examples
  • Communication of thought process and openness to feedback

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

Q2

Given a large existing code repository, identify and fix bugs within the codebase.

Root Cause AnalysisTechnical Trade-offs
Author's notes

This wrecked me.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the bug's symptoms and scope, then systematically narrow down the root cause using debugging tools and code reading. Propose a fix that addresses the root cause, considering trade-offs like performance, maintainability, and side effects, and validate with tests.

Pro tip: Demonstrate a methodical approach: reproduce the bug first, then use binary search or logging to isolate the faulty code. Mention that you'd add a regression test to prevent future occurrences.

1. Understand and Reproduce

Gather details about the bug: expected vs. actual behavior, environment, and steps to reproduce. Reproduce it locally to confirm.

2. Locate the Faulty Code

Use debugging tools, logs, and code search to narrow down the source. Read related code and understand the intended behavior.

3. Identify Root Cause

Analyze why the bug occurs: logic error, edge case, race condition, etc. Consider if it's a symptom of a deeper design issue.

4. Implement and Validate Fix

Write a minimal fix that addresses the root cause. Add or update tests to cover the bug and ensure no regressions.

5. Review and Communicate

Document the fix, explain trade-offs, and communicate with the team. Consider if similar bugs exist elsewhere.

Key Points to Mention

  • Reproducing the bug consistently before attempting a fix
  • Using debugging tools (e.g., breakpoints, logging, profilers) to isolate the issue
  • Reading and understanding the surrounding code and its dependencies
  • Considering trade-offs of different fixes (e.g., quick patch vs. refactor)
  • Adding regression tests to prevent recurrence
  • Communicating findings and fix to the team, and checking for similar issues

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