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

IntermediatePrefer not to say
Jun 2026

Summary

Took the Amazon SDE II OA after casually applying while grinding practice problems. It had four parts: a DSA coding question, a repo/code comprehension task, a system design section, and a work style questionnaire. The coding question threw me off because it didn't feel like standard leetcode, and the repo question wrecked me despite feeling confident after the practice test.

Questions Asked (3)

Q1

Solve a DSA coding problem in the style of the Amazon OA (not a standard leetcode-style problem).

Algorithms & Data Structures
Author's notes

Blanked on it.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem statement and constraints, then outline a brute-force solution before optimizing. Focus on writing clean, modular code with edge cases in mind, and explain your thought process as you go.

Pro tip: Amazon OA problems often involve practical scenarios like optimizing delivery routes or managing inventory; relate your solution to real-world Amazon systems to show business impact.

1. Understand and Clarify

Ask clarifying questions to confirm input/output formats, constraints, and edge cases. Restate the problem in your own words to ensure alignment.

2. Brainstorm Approaches

Discuss potential solutions, starting with a brute-force method, then analyze time and space complexity to identify optimizations.

3. Choose and Explain

Select the optimal approach, justify your choice, and outline the algorithm step-by-step before coding.

4. Code and Test

Write clean, well-structured code with meaningful variable names. Test with provided examples and additional edge cases.

5. Review and Optimize

Review for off-by-one errors, discuss potential improvements, and analyze final complexity.

Key Points to Mention

  • Time and space complexity analysis
  • Edge cases and input validation
  • Modular code with helper functions
  • Trade-offs between different approaches
  • Amazon Leadership Principles like Customer Obsession and Ownership
  • Real-world application to Amazon systems

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

Q2

Given an unfamiliar codebase, read and modify the code to implement specific logic (repo-style question).

API & IntegrationsTechnical Trade-offs
Author's notes

This one hurt.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements and expected behavior, then systematically explore the codebase to locate relevant files and understand the existing architecture. Implement the logic incrementally, writing tests to validate your changes, and ensure your solution aligns with the codebase's patterns and Amazon's engineering standards.

Pro tip: Demonstrate ownership by proactively identifying potential edge cases and discussing how you would handle them, and always consider the impact of your changes on other parts of the system.

1. Clarify Requirements

Ask clarifying questions to fully understand the expected behavior, inputs, outputs, and any constraints. Confirm assumptions before diving into the code.

2. Explore the Codebase

Navigate the repository structure, identify key modules, and trace the flow of data to understand where the new logic should be integrated. Look for existing patterns and conventions.

3. Plan and Implement

Outline your approach, breaking down the task into smaller steps. Write clean, maintainable code that follows the existing style and integrates seamlessly.

4. Test and Validate

Write unit tests to cover the new logic and run existing tests to ensure no regressions. Consider edge cases and error handling.

5. Review and Refactor

Review your changes for quality, performance, and readability. Refactor if necessary and ensure the solution is scalable and aligns with best practices.

Key Points to Mention

  • Understanding the existing architecture and design patterns before making changes
  • Writing tests to validate the new logic and ensure no regressions
  • Considering edge cases and error handling
  • Following coding standards and conventions of the codebase
  • Documenting changes and communicating with the team
  • Evaluating trade-offs between different implementation approaches

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

Q3

System design question as part of the OA.

System Design
Author's notes

Didn't stress about this one much.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements and constraints of the system, then outline a high-level design before diving into details. Focus on scalability, availability, and trade-offs, and be prepared to justify your choices with data and examples.

Pro tip: Amazon values customer obsession and ownership, so tie your design decisions back to customer impact and long-term maintainability. Also, explicitly discuss how you would measure success and handle failures.

1. Clarify Requirements

Ask questions to understand functional and non-functional requirements, such as scale, latency, consistency, and budget. Confirm assumptions with the interviewer.

2. High-Level Design

Sketch the main components (e.g., clients, APIs, services, databases, caches) and how they interact. Keep it simple and focus on the core flow.

3. Deep Dive

Elaborate on critical components: data model, partitioning, replication, load balancing, and caching. Discuss trade-offs and alternatives.

4. Address Bottlenecks and Failures

Identify potential bottlenecks and single points of failure, and explain how to mitigate them (e.g., sharding, redundancy, graceful degradation).

5. Wrap Up and Metrics

Summarize the design, discuss how to monitor and measure performance, and suggest future improvements or extensions.

Key Points to Mention

  • Scalability: horizontal scaling, sharding, and load balancing
  • Availability and fault tolerance: replication, redundancy, and failover
  • Data consistency and CAP theorem trade-offs
  • Caching strategies and CDN usage
  • Monitoring, logging, and alerting for operational excellence
  • Cost optimization and resource efficiency

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