IBM Software Engineer interview questions

32 Software Engineers have shared notes from their IBM interviews, with the questions they were asked in each round. That is 82% of the 39 IBM interview notes on Screna AI.

32 Software Engineer interview notes

IBM·Software Engineer·Online Assessment (OA)

Aug 2026
Did the IBM SWE intern OA which had two parts: a standard leetcode problem and a repo debugging task. Passed all test cases on both and now have no idea if that actually means anything.
  • Solve a coding problem similar to a standard LeetCode-style algorithm question.
  • Given a repository with bugs, identify and fix the issues to make the code work correctly.

“Passed all the test cases so I guess it went fine.”

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IBM·Software Engineer·Online Assessment (OA)

Aug 2026
Took the IBM entry-level software engineering online assessment and the two questions were wildly different in difficulty. The first was a graph/dependency problem that felt manageable, but the second dropped me into a real codebase with failing tests and a spec, which felt less like a coding challenge and more like an actual job.
  • Solve a graph-based dependency problem as part of a timed online assessment.
  • Given an unfamiliar backend repository, a technical spec, and a set of failing tests, debug and fix the application so all tests pass within the time limit.

“Not too bad once I figured out what they were actually asking.”

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IBM·Software Engineer·Technical Phone Screen

Jul 2026
Did a technical interview at IBM for a mid-level role and got hit with a genuinely brutal data structure question. Left feeling confused about what they're actually looking for at that level.
  • Design an LRU Cache that supports TTL-based eviction, a max capacity constraint, and a method to retrieve the running global average of TTL values across all current items. Implement get(key), put(key, value), and get_average().

“This wrecked me.”

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IBM·Software Engineer·Online Assessment (OA)

Jul 2026
Did the IBM HackerRank OA for a software engineer intern role, two questions, one straightforward and one that had me implementing API routes in an IDE environment. Passed and got invited to a competency interview the next day, but had no idea what to expect from that round or what comes after.
  • Implement API routes as part of an IDE-based coding assessment.

“The first question was fine, pretty standard stuff.”

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IBM·Software Engineer·Online Assessment (OA)

Jul 2026
IBM interview with two problems: a hard DP coding question and a Django backend debugging problem. Didn't finish either cleanly, which stings, but here we are.
  • Solve a hard dynamic programming problem under timed conditions.
  • Debug a broken Django backend given a multi-page problem description and supporting documentation.

“Got most of the cases but hit a TLE I couldn't shake.”

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IBM·Software Engineer·Online Assessment (OA)

Jul 2026
Took the IBM entry level SWE online assessment on HackerRank. Two parts: debugging an API repo and a coding problem. The whole thing ended on a sour note because of a last-minute optimization attempt that I couldn't undo before time ran out.
  • Debug a provided repository to fix errors in an API.
  • Write a function that counts the number of unexpired tokens from a given list.

“Passed most test cases on this one, which felt fine at the time.”

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IBM·Software Engineer·Online Assessment (OA)

Jul 2026
IBM OA, 90 minutes, two questions. One greedy problem and one heap problem. Pretty standard format, nothing too wild.
  • Solve a greedy algorithm problem.
  • Solve a heap-based problem.

“No details shared about the specific problem, just that it was greedy-based.”

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IBM·Software Engineer·Technical Phone Screen

Jul 2026
IBM software engineer round, one algorithmic question that looked simple until you actually had to implement it correctly. The sliding window stuff sounds like textbook material but the 'exactly k distinct' constraint has a subtle wrinkle that I did not handle cleanly on the first pass.
  • Given an integer array and an integer k, find the minimum length of a contiguous subarray containing exactly k distinct integer values. Return -1 if none exists.

“I jumped straight to a sliding window and got something working for 'at least k' before realizing the question said 'exactly.' Had to backtrack and rethink the shrink logic.”

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IBM·Software Engineer·Online Assessment (OA)

Jul 2026
Took the IBM entry-level SWE online assessment and it was two very different problems back to back. The first was a graph/dependency thing, manageable once you see the structure. The second dropped you into a real codebase with failing tests and told you to figure it out, which was a completely different experience and nearly ran out the clock.
  • Solve a graph or dependency-based algorithmic problem.
  • Given an existing backend repository and a technical spec, debug failing tests covering API filtering, pagination, and Redis caching including cache invalidation edge cases.

“Not too bad once I stopped overthinking the setup and just mapped out the relationships.”

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IBM·Software Engineer·Technical Phone Screen

Jul 2026
IBM software engineer round, got a scheduling problem that I've seen floating around on leetcode for a while. Nothing too surprising but it's the kind of question where you can fumble the implementation even if you know the idea.
  • Given a list of meeting time intervals, each as a [start, end] pair, find the minimum number of conference rooms needed to accommodate all meetings simultaneously.

“Knew this one.”

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