Amazon OA AI Assistant Bug Fixing Round: What to Expect

Candidates preparing for Amazon in 2026 are running into something the old OA guides do not mention: an Amazon OA AI assistant bug fixing round. It sits next to the familiar two-problem coding test. You are given code that is wrong, an assistant that will happily suggest a patch, and a timer. The thing being measured is whether you can tell a real fix from a confident wrong one.

Details vary by invitation, and Amazon has not published a single public spec for this module. Treat the outline below as the pattern in recent reports, then confirm what your email actually lists. The classic coding section is covered separately in Amazon SDE 1 OA questions 2026.

How the Amazon OA AI assistant bug fixing round works

Reports describe a section that is not "solve a LeetCode problem from a blank file." The starting point is existing code.

What candidates consistently describe:

One or more small programs with a defect
A visible AI assistant inside the assessment, so using it is allowed
Tests, a sample, or a written description of the behavior that is wrong
A timer short enough that you cannot rewrite the program from scratch
A result that depends on the code you submit, not on how polite you were to the assistant

What this is easy to confuse with:

Module	Your job	Assistant
Classic coding OA	Write a solution to a stated problem	No
Older Amazon debugging sets	Find bugs in several short snippets, usually without an AI tool	No
AI assistant bug fixing round	Repair code with an assistant available	Yes, and that is the point

The older debugging OA (a stack of short broken functions, no assistant) still shows up in older write-ups. Do not assume your 2026 link is that test. Read the instructions on the first screen before you skip the chat box or live in it.

What the round is actually scoring

A person who has never used an assistant can still pass, and a person who pastes the first suggestion can still fail. The useful skills are narrower than "be good at AI":

Name the bug before you edit. If you cannot say "the loop uses < and the last index is skipped," you are not ready to accept a patch.
Reproduce it with a test. A failing input is worth more than a theory.
Check the assistant against that test. Run its patch. If the original failure is gone and a new one appeared, revert.
Keep the change small. Rewriting a working function to a different algorithm is how you burn the timer and introduce a second bug.
Leave a regression check. The case that failed at the start should still be in front of you at the end.

InterviewTruth does not have a public answer key for this module. Nobody credible is publishing "the exact bug Amazon used last Tuesday." Practice the skill, not a screenshot.

Bug classes worth drilling

You do not need exotic defects. Assessments like this use bugs a careful reader can find.

Off-by-one and boundaries

for i in range(len(a) - 1):
    if a[i] > best:
        best = a[i]

The last element never competes. Empty input crashes on a different line. Practice saying which input hits which line.

Wrong comparison or sign

A function that should return the minimum returns the maximum because the comparator is flipped, or a "strictly greater" check uses >= and keeps a tie the problem statement excludes. These are invisible if you only test a strictly increasing array.

Mutating the input

The function sorts the caller's list, or appends to a default argument, or swaps two values and forgets one assignment. Add a test that asserts the input is unchanged when the prompt says it should be.

State that leaks between cases

A global counter, a cache that is not cleared, a recursive helper that closes over a list and appends on every call. The sample passes. The second hidden test fails because it ran after the first.

Almost-right algorithmic bugs

The structure is familiar — binary search, BFS, a stack — and one invariant is wrong.

Binary search practice bug: updating lo = mid instead of lo = mid + 1, so a match never terminates.

BFS practice bug: marking a cell visited when it is dequeued instead of when it is enqueued, so the same cell enters the queue many times and the distance is wrong. Or the opposite: marking it visited too early and blocking a second edge that the problem allows.

Stack practice bug: popping after you compare, so the next greater element sees the wrong neighbor. The stack with O(1) getMiddle write-up is a design problem, not an OA bug, but it is the same instinct: know which element is in the middle before you change the structure.

Language traps, not puzzles

Integer division, None versus empty string, mutating a dict while iterating, copying a list with = instead of a shallow copy. If you only practice in one language, practice in that language. The assistant will often "fix" these by rewriting into a style you then cannot debug.

How to use the assistant without handing it the round

Use it for things you would look up in docs if docs were allowed:

The exact library call for a counter, a heap, or a queue
A reminder of whether a method sorts in place
A plain-language restatement of a dense comment

Do not use it as the first move. A reliable order:

Read the function and write the invariant in a comment. ("best is the max of a[0:i] after iteration i.")
Find one input where the invariant breaks. Run it.
Ask the assistant why that input fails, not "fix this."
If the suggestion matches your invariant, apply it and rerun the failing input plus one input that already passed.
If the suggestion is a new algorithm, ignore it unless you can prove yours cannot be repaired in time.

The failure mode this round is built for: the assistant returns code that passes the sample and fails a case you did not ask about. Your job is to be the person who asks.

A practice session that matches the round

You can build this at home in an hour.

Take a correct solution you wrote last month. Array, tree, or BFS. About 30–60 lines.
Break exactly one thing. Flip a comparator, drop a + 1, or forget to mark visited.
Hide the solution. Set a 20-minute timer.
Open a chat model in another window if you want the assistant constraint to be real.
You are done only when you have a failing test from before the fix and a passing run of that same test after.

Do this five times. Then do it on code you did not write — a teammate's pull request, a tutorial you slightly mistrust, a standard library example with one line edited. Reading your own code is easier than reading a stranger's, and the OA will not be your code.

Themes that transfer to the rest of Amazon's process: the coding OA still wants those same structures written correctly (SDE 1 OA guide), and the onsite still wants you to talk about a time you found a real defect before customers did. A bug you actually fixed in a project is a Leadership Principles story. A bug you only found because a model told you is not.

Frequently asked questions

Is the AI assistant bug fixing round in every Amazon OA?

No. Many candidates still get the classic two coding problems plus a work-style survey. Others are seeing a debugging module with an assistant. Your invitation is the source of truth, not a blog post.

Can I ignore the assistant and still pass?

Yes, if you can find and fix the bug yourself. The assistant is available. It is not a requirement to use it, and using it badly is a way to fail.

How is this different from the two coding questions?

The coding section asks you to produce an algorithm from a statement. This section asks you to diagnose code that already exists. Blank-file LeetCode practice helps the first section. It barely helps this one unless you also practice reading.

What should I do if the assistant and the tests disagree?

Trust a test you understand. If you do not understand the test, do not "fix" the code until you can state the expected output by hand. Hidden tests are not something you can argue with after you submit.

Does this replace Leadership Principles?

No. Work-style questions are a separate module, and spoken Leadership Principles show up in every live round. Start with live Amazon interview questions once the OA is done.

Final thoughts

The Amazon OA AI assistant bug fixing round rewards a boring habit: reproduce, patch the smallest line that explains the failure, rerun. The assistant is a fast coworker who is sometimes wrong.

Practice that habit on code you did not write. Then go into the rest of the OA with the plan in Amazon SDE 1 OA questions 2026, and keep an eye on new reports on Amazon interview questions. Good luck.