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

JuniorRejected
Jul 2026Remote

Summary

Took Amazon's OA with barely a week's notice and it showed. Two coding questions, one DP and one Spring Boot, and I bombed both pretty thoroughly.

Questions Asked (2)

Q1

Solve a dynamic programming problem as part of a timed coding assessment.

Algorithms & Data Structures
Author's notes

Passed 3 out of 15 test cases.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem and constraints, then define the DP state and recurrence relation. Implement the solution efficiently, test with examples, and optimize space if possible.

Pro tip: Communicate your thought process clearly and manage your time by tackling the highest-value parts first. If stuck, start with a brute-force solution and then optimize.

1. Understand the problem

Restate the problem in your own words, ask clarifying questions, and identify input/output and constraints.

2. Define DP state and recurrence

Determine what the state represents and how it transitions from smaller subproblems. Write down the recurrence relation.

3. Implement and test

Code the DP solution, starting with a recursive memoized approach if easier, then convert to iterative if needed. Test with provided examples and edge cases.

4. Optimize

Analyze time and space complexity. Consider space optimization techniques like rolling arrays or state compression.

Key Points to Mention

  • Optimal substructure and overlapping subproblems
  • Time and space complexity analysis
  • Base cases and initialization
  • Iterative vs. recursive implementation
  • Space optimization techniques
  • Edge cases and constraints

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

Q2

Build a working backend feature using Spring Boot, passing a set of automated test cases.

API & IntegrationsTechnical Trade-offs
Author's notes

1 out of 6.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements and test cases to understand the expected behavior and constraints. Then design a minimal Spring Boot application that satisfies the tests, focusing on clean API design and integration points. Implement iteratively, running tests frequently to ensure correctness and address edge cases.

Pro tip: Before writing any code, read the test cases carefully to infer the exact API contract and error handling expectations; this saves time and ensures you meet all requirements. Also, consider non-functional aspects like logging and validation early, as they often appear in Amazon's leadership principles.

1. Clarify Requirements and Test Cases

Ask questions to understand the feature scope, expected inputs/outputs, and any constraints. Review the provided test cases to deduce the API endpoints, request/response formats, and error scenarios.

2. Design the Solution

Sketch a high-level design: identify necessary Spring Boot components (controllers, services, repositories), data models, and integration points. Consider trade-offs between simplicity and extensibility.

3. Implement Incrementally

Set up the Spring Boot project with required dependencies. Implement one endpoint or feature at a time, running the relevant tests after each change to validate progress.

4. Handle Edge Cases and Errors

Ensure robust error handling (e.g., validation, exceptions) and cover edge cases like empty inputs, invalid data, or concurrent access. Add logging for observability.

5. Refactor and Verify

Once all tests pass, refactor code for readability and maintainability. Run the full test suite to confirm everything works, and consider performance implications.

Key Points to Mention

  • Understanding the test cases as the specification for the API contract
  • Using Spring Boot starters for web, data JPA, and validation to speed up development
  • Applying RESTful principles and proper HTTP status codes
  • Implementing input validation and global exception handling
  • Writing clean, modular code with separation of concerns (controller, service, repository)
  • Considering scalability and performance trade-offs (e.g., database indexing, caching)

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