20 Amazon Online Assessment Debugging Test Tips with Practice Questions and Answers

Amazon Online Assessment Debugging Test
You can increase your chances of doing well in the Amazon online assessment debugging test by preparing hard for it. Image source: David Becker/AFP.

20 Amazon Online Assessment Debugging Test Tips with Practice Questions and Answers

This article provides information about Amazon’s online debugging test. There are a number of tests that a candidate will be asked to take if they aspire to go into a debugging career at Amazon.

As you continue reading, you will get to know the essential facts about this Amazon online debugging test, how to prepare yourself for the test, and other things that you need to know about it.

As an Amazon online debugging test candidate, you should go through this well-written, well-thought, and well-expressed article to help you know how to solve the test’s questions.

20 Amazon Online Assessment Debugging Test Tips

Here are important facts and tips about Amazon online assessment debugging test to help you prepare effectively and perform excellently in the exam:

  1. Amazon OA1 (Part 1) – Code Debugging Assessment Test

In this section, you will be given seven debugging questions and asked to complete them within 20 minutes. You’ll also be asked to figure out what the functions do, and fix them.

  1. Amazon OA2 (Part 2) – Coding and Workstyles Debugging Assessment Test

You will have two subsections in this test. The 70-minute coding assessment is the first, in which you’ll be required to answer two coding questions.

It’s highly recommended to practice Data Structures and Algorithms to master the OA2.

In a complete course, you can find hundreds of coding problems focusing on the most common Data Structures & Algorithms: Arrays, Stacks, Queues, Linked Lists, Trees, Graphs, and lots more.

  1. Amazon OA3 (Part 3) – Technical Problem Solving Debugging Assessment Test

The work simulation, which is also called “Day-in-the-Life SDE Simulation”, included a logical ability test in earlier years.

You will be given up to four hours to complete the work simulation portion, although many require even less time.

In the scenario-based section, some of the questions will ask you to prioritize potential projects and handle team conflicts, underperforming colleagues, and tight deadlines, and more.

  1. Amazon Coding Assessment Test

In this test, you will be offered coding questions and a Coding Approach Questionnaire, requiring that you explain your preferred approach for solving coding questions.

This test is similar to the Amazon SDE 2 coding challenge’s opening screen, though the coding questions will differ.

  1. Preparing for the Amazon Online Assessment Debugging Test

The best way to prepare for the Amazon online assessment debugging test is to practice materials that are as near as possible to the actual test.

This will help you to know what to anticipate and nothing will push you off target. You will further gain an advantage over your prep time, and not to give your time to practicing broad materials that are far from the test questions.

  1. Becoming Familiar with Coding Under Time Pressure

You should use a timer while you practice coding questions at home as the online code debugging assessment will be timed.

Endeavor to analyze how much time each section consumes and modify it to suit you. An instance of this is the amount of time it takes you to read and understand each question.

If you learn to practice working under time pressure, you won’t be panicked on the assessment day and your coding technique will be more effective.

  1. Focusing on the Logic Behind Your Solutions

Don’t just memorize the answers when practicing the Amazon online assessment debugging test.

It is essential to understand the reasoning and patterns behind the solutions, in order to utilize them on other coding questions.

As Amazon recurrently changes its coding challenges, you may encounter a coding question that hasn’t yet been uploaded to Leetcode.

This won’t trouble you at all if you know the logic behind each solution.

  1. Articulating Your Thought Process in the Amazon Online Debugging Test

You can master several coding questions during self-practice, but describing your solution and thought process in an aggressive situation such as an interview means dragging things to another level.

However, you can improve your skills on the test by getting accustomed to talking and thinking out loud as you code, in order to express your thought process and leave out awkward silences.

Always refer to a coding concept so you don’t use indistinct wording, and break down your coding explanations into logical sequences to make it easier for the interviewer to understand your concept.

  1. The Amazon Leadership Principles Required in the Amazon Online Debugging Test

Amazon is fanatical with its Leadership Principles, so you should answer your questions using them to reach the expectation of the hiring manager.

You must study these Amazon leadership principles if you really want to get hired, and you should use them throughout your assessments and interviews.

Amazon Leadership Principles:

  • Customer Obsession
  • Ownership
  • Invent and Simplify
  • Are Right, A Lot
  • Learn and Be Curious
  • Hire and Develop the Best
  • Insist on the Highest Standards
  • Think Big
  • Bias for Action
  • Frugality
  • Earn Trust
  • Dive Deep
  • Have Backbone; Disagree and Commit
  • Deliver Results.
  1. The Purpose of the Amazon Online Assessment Debugging Test

The purpose of this test is to identify candidates that could do well in the interview.

The test assesses the problem-solving and coding skills of the candidate so they can utilize them on the role that they seek.

The test has some questions that evaluate you against the Amazon Leadership Principles.

The test will be provided on an online code pad tool and you can use most of the admired programming languages.

You can visit the tool and get acquainted with the features before the test day.

Amazon’s online assessment debugging test has two coding questions, and the first is easier than the latter.

In the test, you will be given 90 minutes to complete both questions.

You will get some MCQ questions about Leadership Principles once you’ve submitted the code.

  1. Preparing for the Amazon Assessment Debugging Test with Basic Data Structures

You need to prepare for the Amazon online assessment debugging test with basic data structures like Queue, Graphs, Stack, Binary Search Trees, Linked List, Hash Tables, and Heap.

Learn your way through Heap Sort, Binary Search, Merge Sort, and Quick Sort as sorting and searching become the most popular questions in the test.

Also study DFS, BFS, and tree traversals, and read about the three traversal models such as Pre Order, In Order, and Post Order.

It’s important to study Divide and Conquer, Dynamic Programming, as well as Dijkstra’s and Prim’s algorithms for graph traversal.

You should study how to calculate the time and memory complexity of your code and further endeavor to remember time complexity of classical algorithms.

  1. The Importance of Practicing for the Amazon Online Assessment Debugging Test

Attempting as much practice questions as you can is the key to passing the test. Try to practice with answering several practice algorithmic questions so you can excel in the test.

  1. Your Experience During the Amazon Online Debugging Test

During the Amazon online assessment debugging test, you can access the internet and you’ll be allowed to use IDE.

The risk there is that you will lose everything you are doing if you couldn’t copy-paste your code on time.

  1. Time Management on the Amazon Online Assessment Debugging Test

Excelling in the Amazon online assessment debugging test is about how well you manage your time.

Because of the difficulty of two questions, it becomes hard to complete both of them with the allotted time of 90 minutes.

Don’t waste too much time on the first question if it becomes the easier one.

Try to prioritize the essential bits of the algorithms if you are running out of time.

For instance, prioritize the Comparator since it’s going to be the core logic of the program if you are going to implement a sort.

  1. Write Excellent Code During the Amazon Online Assessment Debugging Test

As this becomes the first time that Amazon is seeing your code, you should give the best first impression.

Follow basics, use meaningful variable and method names, and move the unnecessary code to functions.

Also create classes instead of using complex collections, write comments where necessary, and endeavor to output the best industrial software you can.

  1. Do Not Use Physical Power to Attempt Debugging Questions

You may be tempted to brute-force yourself while solving problems; this is highly discouraged.

Instead of having a 100 percent working code of the brute force solution, it is better to achieve 60 percent of completed code of the best solution.

  1. Get Used to Presenting Before a Webcam

Amazon has now replaced its on-site interviews with virtual interviews as of 2020.

For experienced roles, interviews can last for five hours and between 45 minutes to a few hours for New Grads and Interns.

Coding solutions will focus on virtual whiteboards and interview sessions on behavioral questions.

These interview sessions are not only on behavioral questions, but also coding solutions on virtual whiteboards.

Therefore, ensure you know how to manage it efficiently and without any technical problems that could spoil things.

  1. Three Months of Self-study Before Amazon Code Debugging Test

To be fully prepared for the Amazon online assessment debugging test depends on how much time you dedicate to study.

Your success on the test relies wholly on the amount of time you give to study.

  1. Don’t Stress Out from the Bar Raiser Interview

The code debugging question is definitely going to be hard as the Bar Raiser interviewer will prove difficult on the questions.

The interviewer will ask you about every little detailed answer you provide, and that calls for you to prepare beforehand so as to considerably increase your chances of scoring highly.

  1. Amazon Questions for Debugging Test

The first stage of this test comprises one online debugging test and seven different codes with a detailed explanation and bugs included in them.

What you should do in times of compile-time or runtime errors is to find them and fix the code so that it will exceed all of the test cases.

You need to get at least six to seven correct answers to clear this level because of the 20 minutes of the time limit of this test.

Amazon Code Debugging Practice Questions and Answers

Here are sample questions and answers to practice with for a successful Amazon online assessment debugging test:

  1. Find the missing number in the array

You are given a collection of positive numbers from 1 to n, where all numbers from 1 to n are present except one number x. You have to find x.

The input array is not sorted. Have a look at the below collection and give it a try before checking the solution.

3 7 1 2 8 4 5

n = 8 missing number = 6

Runtime Complexity: Linear, O(n)O(n)O(n)

Memory Complexity: Constant, O(1)O(1)O(1)

To simply search for every integer between 1 and n in the input collection is a naive solution, ending the search once there is a missing number.

But we can do better. This linear, O(n)O(n)O(n), is a solution that uses the arithmetic series sum formula.

Below are the steps to follow to find the misplaced number:

  • Look for the sum sum_of_elements of all the numbers in the collection. This would require a linear scan, O(n)O(n)O(n).
  • Then look for the sum expected_sum of first n numbers using the arithmetic series sum formula.
  • The difference between these, expected_sum – sum_of_elements, is the missing number in the collection.
  1. Join two sorted linked lists

Join two sorted linked lists given to you, so that the resulting linked list is also sorted. Think about two sorted linked lists and the joined list below them as an example.

head1 4 8 15 19 NULL
head2 7 9 10 16 NULL
head1 4 7 8 9 10 15 16 19 NULL

This is Runtime Complexity: Linear, O(m+n)O(m + n)O(m+n) where m and n are lengths of both linked lists

This is Memory Complexity: Constant, O(1)O(1)O(1)

Look at the joined linked list and maintain a head and a tail pointer. By comparing the first node of both linked lists, select the head of the joined linked list.

You choose the smaller current node for all subsequent nodes in both lists and link it to the tail of the joined list, and then move the current pointer of that list one step forward.

Go on with this while there are some elements left in both lists. Link this remaining list to the tail of the joined list if there are still some elements in only one of the lists. Initially, the joined linked list is NULL.

Evaluate the value of the first two nodes and make the node with the smaller value the head node of the joined linked list. In this example, it is 4 from head1.

It will also be the tail since it’s the first and only node in the joined list. Then move head1 one step forward.

  1. Copy linked list with arbitrary pointer

You are provided with a linked list where the node has two pointers. The first is the regular next pointer.

Arbitrary_pointer is the second pointer and it can point to any node in the linked list.

You are required to write code to make a deep copy of the given linked list.

Deep copy here implies that any operations on the original list should not affect the copied list.

Runtime Complexity: Linear, O(n)O(n)O(n)

Memory Complexity: Linear, O(n)O(n)O(n)

This method makes use of a map to track arbitrary nodes pointed by the original list. You will make a deep copy of the original linked list like list_orig in two passes.

  • Make a copy of the original linked list in the first pass. Use the same values for data and arbitrary_pointer in the new list while making this copy. In addition, continue keeping up to date the map with entries where the key is the address to the old node and the value is the address of the new node.
  • Do another pass on the copied linked list once the copy has been created, and update arbitrary pointers to the new address using the map created in the first pass.
  1. Level Order Traversal of Binary Tree

Display the node values at each level from the root of a binary tree. Display node values for all levels on separate lines. Have a look at the binary tree below.

100 50 200 25 75 350

Here is a sample level order traversal for this tree: 100; 50, 200; 25, 75, 350

Runtime Complexity: Linear, O(n)O(n)O(n)

Memory Complexity: Linear, O(n)O(n)O(n)

Current_queue and next_queue are two queues that you are using. Nodes in both queues should be pushed by preference based on the current level number.

Nodes from the current_queue should be dequeued, the node’s data printed, and the node’s children enqueued to the next_queue.

You have processed all nodes for the current level_number once the current_queue becomes empty.

Print a line break (\n), swap the two queues and continue with the above-mentioned logic to indicate the new level.

Swap current_queue and next_queue after printing the leaf nodes from the current_queue.

You can terminate the loop since the current_queue would be empty.


Passing the online assessment debugging test is the first step to getting a code debugging job at Amazon.

You will be required to take the code debugging test, which lasts for 20 minutes.

In that test, you will be asked to fix and make changes so the patterns shown can run correctly.

Most of these problems are errors with parameters, syntax, operators, and so on.

You will be monitored during the test, so you should abide by the rules.

Engage in personal assignments to help you with the basic understanding of algorithms.

Be conscious of the limited amount of time during the test, and take your time to read each question carefully before attempting them.

>> Are you billed to take a pre-employment assessment test with a company? If you are, then it is wise to learn about the test and prepare effectively for it with lots of practice questions and answers. Start your preparation for your coming test here: Make Top Scores in Employers’ Assessment Tests.