Amazon Online Assessment (OA) 2025 Guide

 

Amazon Online Assessment (OA)

The email lands in your inbox: “You are invited to complete Amazon’s Online Assessment.”

Your heart jumps. It’s a milestone; you’ve passed the résumé screen at one of the world’s most selective employers. But then reality sinks in. The Amazon Online Assessment (OA) is a timed, remote test designed to evaluate your thinking under pressure. Candidates often say it feels like a real Amazon workday compressed into a few hours.

This guide is built from real candidate experiences, official Amazon guidance, and problem-solving frameworks that consistently appear in the Amazon OA. Along the way, we’ll cover Amazon’s most asked behavioral questions, show you sample Amazon OA questions with solutions, and share tips for interview preparation for Amazon roles.

What the Amazon OA Tests

Amazon explains on its careers page that the OA is a three-part evaluation: coding, work simulation, and work style.

The coding section includes two or three algorithmic problems, usually focused on arrays, strings, hash maps, and graphs. You get 70 to 90 minutes, depending on the role. This portion is sometimes called the Amazon SDE Online Assessment.

The work simulation presents scenario-based challenges. You have to decide how to prioritize tasks, communicate with teammates, and make tradeoffs. All of this is tied to Amazon’s Leadership Principles.

The work style assessment is more like a questionnaire. It looks at how you naturally approach work. Recruiters confirm that this section is not just a formality. A strong score here can set you apart when many candidates perform similarly in the coding portion.

The Amazon OA in 2025 - What has Changed

The Amazon OA is no longer the same test it was a few years ago. Recent candidate reports show that plagiarism filters are stricter and that Amazon has added new types of problems, such as DNA sequence matching and maximum greyness detection.

The test order is not fixed. Some candidates start with the coding portion, while others begin with work simulation or work style. Amazon has also allowed short breaks between sections, but the timer does not pause once a coding session begins. Candidates now need to balance accuracy, speed, and decision-making in a way that mirrors actual work.

How to Prepare for the Amazon OA

Before you open the test link, check these boxes:

  • Review core coding patterns like sliding window, two pointers, BFS/DFS, and greedy approaches.
  • Candidates should practice answering Amazon’s most asked behavioral questions under timed conditions to avoid freezing during the real OA.
  • Practice in plain text environments where you do not get autocomplete or syntax suggestions.
  • Simulate test conditions by solving two problems in 70 minutes at least three or four times.

Common Amazon OA Problem Types

Based on LeetCode and Reddit discussions, the Amazon online assessment questions that show up most often are:

  • String manipulation, such as substrings and DNA sequences

These questions often test how well you can handle edge cases like overlapping substrings or repeating patterns. Efficiency matters because brute-force solutions tend to time out on large inputs.

  • Array-based questions like rotations and prefix sums

Arrays are a favorite because they check both algorithmic skill and attention to detail. Expect variations where you’ll need to balance time complexity with memory use.

  • Graph traversal problems, such as shortest paths

These usually appear in the form of grids, dependency chains, or navigation tasks. Candidates who practice BFS and DFS under time limits perform much better here.

  • Greedy optimization problems that ask you to minimize steps

These test whether you can spot patterns quickly and avoid over-engineering. The right greedy choice can simplify what looks like a complex dynamic programming problem.

  • Occasional dynamic programming problems are more common for senior levels.

Though less frequent, DP questions separate advanced candidates from entry-level ones. They often appear in roles beyond SDE-1, where optimization and scalability are critical.

These are not just coding drills. Amazon interview coding questions often test whether you can reason about tradeoffs while explaining your approach.

Worked Examples

Example 1: Maximum Average Subarray

Problem: Given an array of integers and a number k, return the maximum average of any contiguous subarray of length k.

Solution: Use a sliding window. Compute the sum of the first window and then update the sum as you slide forward.

def findMaxAverage(nums, k):
    window_sum = sum(nums[:k])
    max_sum = window_sum

    for i in range(k, len(nums)):
        window_sum += nums[i] - nums[i-k]
        max_sum = max(max_sum, window_sum)

    return max_sum / k
Time complexity: O(n)
Space complexity: O(1)

Example 2: Minimum Steps to Make an Anagram

Problem: You are given two strings s and t of equal length. Return the minimum number of steps to make t an anagram of s.

Solution: Count character frequencies. Subtract counts of characters in t from s and sum the positive values.

from collections import Counter

def minSteps(s, t):

count_s = Counter(s)

count_t = Counter(t)

steps = 0

for char in count_s:

if count_s[char] > count_t.get(char, 0):

steps += count_s[char] - count_t.get(char, 0)

return steps

Time complexity: O(n)

Space complexity: O(1) since alphabet size is fixed

Candidate Insights on Amazon OA (2024–25)

Hearing directly from people who have taken the OA makes the preparation feel more real. Here are a few experiences shared by recent candidates:

  • Onecandidate on LeetCode wrote:

    I was asked two coding questions as part of OA for 90 minutes. … Given an array, find the number of sub-arrays whose max-min value ≤ k. … I was able to complete it using sliding window + monotonic queues.

  • Acandidate on Reddit described the Work Simulation:

    The work simulation is exactly what it sounds like. You have an interface where you get emails and chat messages from your ‘colleagues’, and then it gives you choices on what the best path moving forward would be.

  • Anothercandidate added:

    During the simulation, you will be prompted with emails, videos, and instant messages from your virtual managers and team members to solve various problems.

Together, these stories underline a key truth: Amazon OA questions aren’t only about algorithms. They also measure judgment, prioritization, and how closely your thinking aligns with Amazon’s leadership principles.

Mock 2-Week Prep Plan

Here’s a compact plan if your online assessment Amazon invite is two weeks away:

Week 1

  • Days 1–2: Arrays + sliding window.
  • Days 3–4: Graph/BFS/DFS problems.
  • Day 5: Mock OA (2 problems, 70 minutes).
  • Day 6–7: Behavioral prep; review Amazon’s most asked behavioral questions.

Week 2

  • Days 1–2: Hash maps, greedy problems.
  • Days 3–4: Full mock OA (coding + Work Simulation).
  • Day 5–6: Work Style practice, align answers with Amazon in interview questions.
  • Day 7: Review everything.

Wrapping Up and Next Steps

Don’t think of the Amazon OA as a set of riddles; it’s really Amazon’s way of testing how you solve problems under pressure. With the right mix of practice, mindset prep, and familiarity with different formats of Amazon online assessment questions can dramatically cut down test anxiety.

Every Amazon engineer who cleared the online assessment once stood exactly where you are now, nervous but determined. The difference comes down to preparation: drilling core patterns, practicing under timed conditions, and reviewing Amazon’s most asked behavioral questions so your answers reflect the Leadership Principles.

If you’re looking for structured guidance,InterviewHelp’s coaching programs can fast-track your preparation. Reviewing Amazon most asked behavioral questions repeatedly ensures your responses align with leadership principles and sound confident. We offer 1:1 coaching, mock Amazon OA sessions, and tailored feedback from mentors who have successfully navigated FAANG interviews. You can also check out our detailed resources on interview preparation for Amazon and our breakdown of Amazon coding interview questions to round out your study plan.

Good luck on your journey. Remember, you’re not just solving problems, you’re showing how you think. And with consistent practice, you’ve got this.


FAQs

  1. What is the Amazon Online Assessment, and how is it structured?

    The Amazon Online Assessment is a multi-part test including coding challenges, Work Simulation, and Work Style. For SDE roles, coding is the heaviest section, while simulation tests decision-making aligned with Amazon’s Leadership Principles.

  2. What types of Amazon OA questions should I expect in 2025?

    Most common Amazon OA questions 2025 include sliding window problems, graph traversal, string manipulations, and greedy optimizations. Expect 2–3 coding problems in 70–90 minutes.

  3. How do I prepare for Amazon’s most asked behavioral questions?

    Focus on the Leadership Principles. Many of Amazon’s most asked behavioral questions revolve around ownership, customer obsession, bias for action, and delivering results. Use the STAR method (Situation, Task, Action, Result).

  4. Where can I find interview questions from Amazon coding rounds?

    You can practice interview questions from Amazon on LeetCode, Interviewhelp.io , AOneCode, and Educative. You can find both coding and behavioral interview questions from Amazon across prep platforms and candidate write-ups. Many candidates share fresh Amazon coding interview questions from their OA and onsite experiences.

  5. Is the Amazon assessment test the same as the OA?

    The term Amazon assessment test is broader; it covers OAs, Work Simulation, and behavioral assessments. For technical roles, the Amazon SDE Online Assessment is the most common format.

  6. How should I start preparing for Amazon interview coding questions?

    Start with preparing for Amazon interview basics: arrays, strings, BFS/DFS. Drill down into Amazon interview coding questions from past OAs, and build a 2-week study plan to simulate real test conditions.