Whether you're applying for a Software Development Engineer (SDE) internship or a new grad full-time position, the Amazon Online Assessment (OA) is the first and most critical step in the recruitment process.
Failing the OA usually means you’re out — but passing it means you're one step closer to landing the offer.
In this comprehensive guide, we’ll walk you through:
- What the Amazon OA consists of
- The most tested coding patterns
- Smart time and complexity strategies
- How to prepare in just 2 weeks
- Pro tips and tools to maximize your chance of success
What's in the Amazon OA?
Amazon’s OA is delivered through Codility or HackerRank, and typically includes two main parts:
OA1 – Technical Coding Challenge
- 2 coding problems (LeetCode-style, mostly Medium difficulty)
- Duration: ~90 minutes
- Graded on: correctness, performance, edge case handling
- Supported languages: Python, Java, C++, etc.
Amazon OA2 – Work Simulation
- A behavioral assessment (no coding)
- Multiple-choice scenarios testing your response to workplace dilemmas
- Based on Amazon’s 16 Leadership Principles
Note: OA3 (Debugging challenge) may appear for some locations or roles, but OA1 + OA2 is the standard for 2025.
What Are the Most Common Technical OA Patterns?
Amazon’s coding challenges tend to revolve around the following key algorithms:
1. Sliding Window / Two Pointers
Common for longest subarrays, substrings, or optimal windows
Example: Longest Subarray With Sum ≤ K
2. Hash Maps / Frequency Counters
For counting duplicates, mapping values, or frequency-based logic
Example: Top-K Frequent Elements in a Window
3. Greedy Algorithms
Minimizing steps, optimizing distribution, scheduling
Example: Min Operations to Equalize Array
4. Prefix Sum / Difference Arrays
For subarray sum queries and matrix calculations
Example: Subarray Sum Equals K
5. Sorting + Binary Search
For value lookups, thresholds, range constraints
Example: K Closest Points to OriginTip: These problems often have tight time limits — you’ll need efficient solutions (O(n) or O(n log n)), not brute force.
How to Pass Amazon OA With Confidence
Tip 1: Think About Time Complexity First
Amazon’s test cases are huge. Brute-force (O(n²)) usually fails on large datasets.
- Use
HashMap,Set, orPrefix Sumto speed up - Eliminate nested loops when possible
- Learn key tricks for optimization (e.g. sliding window tricks)
Tip 2: Master Time Management
You’ll have ~45 minutes per problem. Suggested time split:
- First 10 min: read and understand problem, plan approach
- Next 25 min: implement and pass basic cases
- Final 10 min: cover edge cases and optimize
If you're stuck for over 10 minutes, switch to the other problem to avoid zero score.
Tip 3: Always Test Edge Cases
Amazon hides edge-case traps. You should always test:
- Empty arrays/strings
- Duplicates
- Large negative/positive values
- K = 0, K = array.length
- Sorted input vs unsorted input
Write custom test cases for validation before submission.
Tip 4: Prepare for OA2 Behavior Simulation
The Work Simulation assesses how well your decisions align with Amazon's values, such as:
- Customer Obsession
- Bias for Action
- Dive Deep
- Earn Trust
If unsure between two answers, choose the one that:
- Prioritizes customers
- Takes initiative
- Respects data over ego
- Shares responsibility
Real Feedback From Candidates
“I thought I aced it, but missed edge cases and got 0 on problem 2. Lesson learned: always test with your own inputs.”
— MSCS Student, University of Toronto“ProgramHelp’s timed mock tests made a huge difference. The real OA felt familiar, and I finished both questions with time to spare.”
— SDE Intern, now full-time at Amazon
Tools & Resources to Use
- LeetCode (Amazon tag, Medium difficulty)
- Blind 75 Problems – curated list of must-know problems
- HackerRank Practice Sets – get used to interface
- ProgramHelp Amazon OA Package – full question bank, mock exams, live tutoring
- YouTube (NeetCode, Tushar Roy) – for solution walkthroughs
🎓 How ProgramHelp Can Support You
With a 92% OA pass rate, ProgramHelp offers:
- Amazon OA real question walk-throughs
- 1-on-1 tutoring for OA and VO rounds
- Live timed mock OA tests
- Resume review & behavioral interview coaching
- OA code debugging & optimization sessions
Explore more: https://programhelp.net
✅ Final Words: Your OA Strategy = Your Success Strategy
Amazon OA isn’t about being a genius — it’s about being prepared, efficient, and focused.
By mastering the key patterns, respecting the time limit, and sharpening your edge-case thinking, you’ll maximize your chances of passing and getting that coveted SDE interview.
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