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Amazon·Software Engineer·Online Assessment (OA)·Junior

JuniorPending
Aug 2026

Summary

Did the Amazon SDE Intern OA and it was a mixed bag. One coding problem was a legit harder medium using prefix/suffix sums and I dropped one test case, while the AI-assisted task went smoothly with all TCs passing and the feature fully built out.

Questions Asked (2)

Q1

Solve a medium-difficulty coding problem involving prefix and suffix sums.

Algorithms & Data Structures
Author's notes

Got most of it but one test case slipped through.

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AI HintsAI Generated

Suggested Approach

First, clarify the problem and constraints, then discuss a brute-force approach and its time complexity. Next, explain how prefix and suffix sums can optimize the solution by precomputing cumulative sums to avoid redundant calculations. Finally, walk through the optimized algorithm, analyze its time and space complexity, and test with edge cases.

Pro tip: At Amazon, always tie your solution back to customer impact: mention how efficient algorithms reduce latency and scale to millions of users, aligning with Amazon's Leadership Principles like Customer Obsession and Deliver Results.

1. Clarify the problem

Ask clarifying questions to ensure you understand the input, output, constraints, and edge cases. Confirm the expected time and space complexity.

2. Discuss brute-force

Propose a straightforward solution, analyze its time complexity, and identify inefficiencies that prefix/suffix sums can address.

3. Design optimized approach

Explain how to compute prefix and suffix sums in one or two passes, and how to use them to solve the problem efficiently.

4. Walk through example

Trace the algorithm on a sample input, including edge cases like empty array or single element, to demonstrate correctness.

5. Analyze and test

State the final time and space complexity, and discuss potential optimizations or trade-offs. Write pseudocode or actual code if required.

Key Points to Mention

  • Time and space complexity trade-offs between brute-force and optimized solutions
  • Handling edge cases such as empty arrays, single elements, or large inputs
  • In-place computation to reduce space complexity when possible
  • Using prefix/suffix sums to avoid redundant calculations
  • Amazon Leadership Principles: Customer Obsession, Deliver Results, Dive Deep
  • Scalability and real-world impact of efficient algorithms

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

Complete an AI-assisted coding task where you implement a feature with the help of an AI tool.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

All test cases passed and the feature worked end to end, so no complaints there.

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AI HintsAI Generated

Suggested Approach

Demonstrate a structured approach to AI-assisted coding by first clarifying requirements and constraints, then using AI to generate initial code while critically evaluating its correctness and efficiency. Emphasize testing, iteration, and explaining trade-offs to show you can leverage AI effectively without compromising engineering rigor.

Pro tip: Treat the AI as a junior pair programmer: verify its suggestions with tests and edge cases, and be ready to explain why you accepted or rejected its output. This shows you can use AI to accelerate work while maintaining high standards.

1. Clarify Requirements and Constraints

Ask clarifying questions to understand the feature's functional and non-functional requirements, such as input/output, edge cases, performance, and scalability. This ensures you and the AI are solving the right problem.

2. Plan the Approach

Outline a high-level design, including data structures and algorithms, before involving AI. This helps you guide the AI effectively and evaluate its suggestions against your plan.

3. Leverage AI for Implementation

Use the AI tool to generate code snippets or full implementations based on your plan. Prompt it with specific requirements and constraints to get relevant output.

4. Review and Test AI Output

Critically review the AI-generated code for correctness, efficiency, and style. Write tests, including edge cases, to validate the solution and identify any issues.

5. Iterate and Explain Trade-offs

Refine the code based on test results and discuss alternative approaches, highlighting trade-offs in time/space complexity, readability, and maintainability.

Key Points to Mention

  • Importance of understanding requirements before coding
  • Using AI as a tool to accelerate development, not replace critical thinking
  • Testing and validating AI-generated code with edge cases
  • Analyzing time and space complexity of the solution
  • Discussing trade-offs between different implementations
  • Demonstrating ability to explain and justify code decisions

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.