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Amazon Web Services·Software Engineer·Onsite - Multi Round·Junior

JuniorPrefer not to say
Apr 2026Boston

Summary

Did the Amazon AWS SDE 1 loop in Boston, four rounds back to back, mix of coding, project deep dives, and behavioral. Interviewers were professional but the whole thing was pretty intense. Felt fair though, not trying to trick you, just really want to see how you think.

Questions Asked (9)

Q1

Walk me through your thought process as you approach this coding problem.

Algorithms & Data Structures
Author's notes

They stopped me pretty early and asked me to just talk through what I was thinking before writing anything.

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AI HintsAI Generated

Suggested Approach

Narrate your problem-solving process in a clear, step-by-step manner, starting with restating the problem and clarifying constraints. Emphasize trade-offs and decision points, and conclude by discussing testing and edge cases.

Pro tip: Show that you think about scalability and real-world constraints from the start—Amazon values engineers who consider how solutions perform at scale and under failure.

1. Clarify the problem

Restate the problem in your own words and ask clarifying questions about inputs, outputs, constraints, and edge cases to ensure full understanding.

2. Explore approaches

Brainstorm multiple algorithms or data structures, discussing their time and space complexities and trade-offs.

3. Select and justify

Choose the best approach based on constraints and explain why it’s optimal, mentioning any assumptions.

4. Outline implementation

Describe the steps to implement the solution, including key data structures and control flow, without writing full code.

5. Test and validate

Walk through testing the solution with normal and edge cases, and discuss how you would handle failures or optimizations.

Key Points to Mention

  • Clarifying questions to uncover constraints and edge cases
  • Time and space complexity analysis for each approach
  • Trade-offs between different algorithms or data structures
  • Scalability and performance considerations for large inputs
  • Testing strategy including edge cases and potential failures
  • Clear communication and structured thinking

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

Q2

Can you improve or adjust your solution based on this follow-up constraint?

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

Second round threw a wrinkle at my original approach and I had to pivot mid-solution.

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AI HintsAI Generated

Suggested Approach

Restate the new constraint clearly, then explain how it affects your original solution's correctness, time/space complexity, and edge cases. Walk through a concrete adjustment—such as changing the data structure, algorithm, or trade-off—and validate it against the constraint with a quick example or complexity analysis.

Pro tip: Frame the adjustment as a deliberate trade-off: acknowledge what you gain (e.g., lower latency, less memory) and what you give up (e.g., extra preprocessing, higher write cost), which signals engineering maturity to AWS interviewers.

1. Clarify the constraint

Repeat the follow-up constraint in your own words and confirm assumptions (e.g., input size, latency budget, memory limits) before proposing changes.

2. Assess impact on original solution

Identify which parts of your current approach break or degrade—correctness, time complexity, space complexity, or scalability—under the new constraint.

3. Propose a concrete adjustment

Describe a specific modification (e.g., swap a hash map for a sorted array, add caching, use a heap, stream instead of store) and explain why it addresses the constraint.

4. Analyze trade-offs and complexity

Compare the adjusted solution to the original in terms of time/space complexity, code complexity, and operational cost, and state which trade-off you accept and why.

5. Validate with an example

Walk through a small example or edge case to show the adjusted solution works and meets the constraint, then summarize the final approach.

Key Points to Mention

  • Time and space complexity before and after the adjustment
  • Data structure or algorithm choice that directly addresses the constraint
  • Trade-offs between performance, memory, and code maintainability
  • Edge cases and correctness under the new constraint
  • Scalability implications relevant to AWS-scale systems
  • Clear reasoning for why the adjusted solution is preferable

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

Q3

What were the key architectural decisions you made in this project, and why did you choose those technologies?

System DesignTechnical Trade-offs
Author's notes

This is where I felt most comfortable and most exposed at the same time.

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AI HintsAI Generated

Suggested Approach

Choose one or two key architectural decisions from a project you know deeply, and walk through them using a structured narrative: context, options considered, decision criteria, trade-offs, and outcome. Emphasize why the chosen technologies fit the requirements and constraints, and quantify impact where possible.

Pro tip: Frame decisions as trade-offs rather than absolute right choices, and explicitly mention what you gave up—this shows architectural maturity and aligns with Amazon's emphasis on trade-off analysis.

1. Set the context

Briefly describe the project's goals, scale, and constraints (e.g., latency, cost, team size) so the interviewer understands the decision environment.

2. State the decision and alternatives

Clearly name the architectural decision and list the main alternatives you considered, showing you evaluated multiple options.

3. Explain the decision criteria

Describe the factors that drove your choice—such as scalability, operational overhead, team expertise, or time-to-market—and how you weighted them.

4. Discuss trade-offs and risks

Acknowledge what you sacrificed with the chosen technology and how you mitigated potential downsides.

5. Share the outcome and lessons

Quantify the impact (e.g., performance gains, cost savings) and reflect on what you learned or would do differently.

Key Points to Mention

  • Specific technologies (e.g., AWS services like Lambda, DynamoDB, SQS) and why they fit the use case
  • Scalability and performance considerations (e.g., horizontal scaling, latency requirements)
  • Operational trade-offs (e.g., managed services vs. self-hosted, maintenance burden)
  • Cost implications and how the decision affected the budget
  • Team factors (e.g., existing expertise, learning curve, hiring needs)
  • Measurable outcomes (e.g., reduced latency by X%, decreased operational costs by Y%)

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

Q4

How did you handle hallucinations in your GenAI work, and what approaches did you use to reduce them?

Technical Trade-offsRoot Cause Analysis
Author's notes

Didn't expect this to go as deep as it did.

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AI HintsAI Generated

Suggested Approach

Start by defining what hallucinations meant in your GenAI project and their impact, then walk through a specific example using a structured problem-solving narrative. Highlight the root causes you identified and the trade-offs you made when implementing mitigation strategies, emphasizing measurable outcomes.

Pro tip: Quantify the reduction in hallucinations (e.g., 'reduced from 15% to 3%') and mention how you balanced mitigation with cost and latency—AWS values pragmatic engineering that considers operational impact.

1. Set the context

Briefly describe the GenAI application, its purpose, and why hallucinations were a critical issue (e.g., customer trust, compliance).

2. Identify root causes

Explain how you diagnosed the sources of hallucinations, such as ambiguous prompts, lack of grounding data, or model limitations.

3. Describe mitigation strategies

Detail the approaches you implemented, such as retrieval-augmented generation (RAG), prompt engineering, fine-tuning, or output validation.

4. Discuss trade-offs

Highlight the trade-offs you considered, like latency vs. accuracy, cost of additional API calls, or complexity of maintaining a knowledge base.

5. Share results and lessons

Quantify the improvement (e.g., reduced hallucination rate) and reflect on what you learned or would do differently.

Key Points to Mention

  • Retrieval-augmented generation (RAG) with a curated knowledge base to ground responses
  • Prompt engineering techniques like few-shot examples and chain-of-thought to guide the model
  • Output validation and guardrails, such as fact-checking against trusted sources or using a secondary model
  • Fine-tuning or instruction tuning on domain-specific data to reduce spurious outputs
  • Monitoring and evaluation metrics (e.g., hallucination rate, user feedback) to measure effectiveness
  • Trade-offs between accuracy, latency, cost, and system complexity

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

Q5

What trade-offs, challenges, and results came out of the project you described, and what would you change now?

Technical Trade-offsSystem Design
Author's notes

The 'what would you change' part got me.

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AI HintsAI Generated

Suggested Approach

Use a structured narrative like STAR to describe the project, then explicitly discuss trade-offs, challenges, and results. End with a reflective 'what I'd change' that shows growth and learning.

Pro tip: Frame trade-offs as deliberate decisions with clear rationale, and tie your 'what I'd change' to a concrete lesson that you've already applied elsewhere—this shows self-awareness and continuous improvement.

1. Set the context briefly

Summarize the project's goal, your role, and the scale or impact in 1-2 sentences to ground the listener.

2. Explain key trade-offs

Describe 1-2 major trade-offs you made (e.g., consistency vs. availability, build vs. buy) and why you chose one over the other.

3. Highlight challenges and how you overcame them

Pick a significant technical or organizational challenge, explain its impact, and detail your solution and the outcome.

4. Quantify results

Share measurable outcomes (e.g., latency reduction, cost savings, adoption metrics) to demonstrate impact.

5. Reflect on what you'd change

Identify one or two things you'd do differently now, explain why, and mention how you've applied that lesson since.

Key Points to Mention

  • Specific trade-offs (e.g., performance vs. cost, scalability vs. simplicity) with rationale
  • Challenges such as technical debt, scaling issues, or cross-team dependencies
  • Quantifiable results (e.g., reduced latency by X%, saved $Y, increased throughput)
  • Lessons learned and how they influenced your subsequent work
  • Alignment with Amazon Leadership Principles (e.g., Customer Obsession, Ownership, Invent and Simplify)
  • A concrete change you'd make now and why it would improve the outcome

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

Q6

Tell me about a time you took ownership of something that wasn't technically your responsibility.

Adaptability & Ambiguity
Author's notes

Classic ownership question.

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AI HintsAI Generated

Suggested Approach

Use the STAR method to describe a specific situation where you identified a gap outside your assigned scope, took initiative to address it, and delivered measurable impact. Emphasize your decision-making process, collaboration with stakeholders, and the results achieved, highlighting Amazon's Leadership Principles like Ownership and Bias for Action.

Pro tip: Choose an example where you influenced without authority and connected your actions to customer or business impact—Amazon values 'Ownership' as thinking long-term and not saying 'that's not my job.'

1. Set the Scene

Briefly describe the project, your role, and the gap or issue you noticed that was outside your formal responsibilities.

2. Explain Your Decision

Share your thought process: why you decided to take ownership, what risks you considered, and how you aligned with stakeholders.

3. Describe Your Actions

Detail the concrete steps you took—how you collaborated, communicated, and executed the work while managing your existing responsibilities.

4. Highlight the Outcome

Quantify the results: time saved, revenue impact, customer satisfaction, or team efficiency. Mention any recognition or lasting process improvements.

5. Reflect and Connect

Summarize what you learned and tie it back to Amazon's Leadership Principles, showing how this mindset drives success at AWS.

Key Points to Mention

  • Demonstrated initiative and bias for action
  • Collaboration and influence without authority
  • Customer or business impact of your actions
  • Ownership mindset aligned with Amazon Leadership Principles
  • Measurable results or outcomes
  • Learning and growth from the experience

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

Q7

Describe a situation where you made a significant mistake and how you handled it.

Root Cause Analysis
Author's notes

Told a real story about a bug I shipped that caused downstream issues.

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AI HintsAI Generated

Suggested Approach

Use the STAR method to describe a specific mistake, focusing on the root cause analysis and the corrective actions taken. Emphasize what you learned and how you implemented changes to prevent recurrence, aligning with AWS's emphasis on ownership and continuous improvement.

Pro tip: Choose a mistake that had real impact but was resolved successfully, and highlight the systemic fix you implemented—this shows you think beyond quick fixes and drive long-term improvements.

1. Set the context

Briefly describe the project, your role, and the situation to give the interviewer enough background to understand the mistake's significance.

2. Describe the mistake

Clearly state what went wrong, its impact, and your immediate reaction—own it without deflecting blame.

3. Analyze root cause

Explain how you investigated to find the underlying cause, using tools like the '5 Whys' or fishbone diagram, and share your findings.

4. Detail corrective actions

Describe the steps you took to fix the issue and prevent recurrence, including any process improvements or automation you introduced.

5. Share learnings and growth

Summarize what you learned and how it changed your approach, emphasizing personal growth and benefits to the team.

Key Points to Mention

  • Ownership and accountability: taking full responsibility for the mistake.
  • Root cause analysis techniques (e.g., 5 Whys, fishbone diagram) to identify underlying issues.
  • Corrective actions: immediate fix and long-term preventive measures.
  • Systemic improvements: process changes, automation, or documentation to prevent recurrence.
  • Learnings: how the experience improved your skills or decision-making.
  • Impact: positive outcomes from the fix, such as increased reliability or team efficiency.

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

Q8

How have you handled a conflict with a teammate or stakeholder, and what was the outcome?

Conflict ResolutionStakeholder Management
Author's notes

Short answer: pick a real conflict, not a fake one where everyone ends up happy and learns a lesson.

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AI HintsAI Generated

Suggested Approach

Use the STAR method to structure your answer, focusing on a specific conflict you resolved through empathy, data-driven discussion, and collaboration. Highlight how you listened to the other party's perspective, communicated your own viewpoint clearly, and worked together to find a solution that benefited the team and the project.

Pro tip: Emphasize that you sought to understand the other person's perspective first and used data or objective criteria to resolve the disagreement, showing maturity and alignment with Amazon's Leadership Principles like 'Have Backbone; Disagree and Commit' and 'Earn Trust'.

1. Set the context

Briefly describe the situation and the conflict, including the parties involved and the stakes. Keep it concise to focus on your actions.

2. Explain your approach

Detail the steps you took to address the conflict, such as setting up a private conversation, actively listening, and seeking to understand the other person's viewpoint.

3. Describe the resolution

Explain how you collaborated to find a mutually agreeable solution, possibly using data or compromise, and how you ensured buy-in from all parties.

4. Highlight the outcome

Share the positive results of the resolution, such as improved team dynamics, project success, or strengthened relationships, and what you learned.

Key Points to Mention

  • Active listening and empathy to understand the other person's perspective
  • Clear and respectful communication of your own viewpoint
  • Use of data or objective criteria to evaluate options
  • Collaboration to find a win-win solution
  • Commitment to the final decision even if it wasn't your first choice (Disagree and Commit)
  • Positive outcome and lessons learned for future conflicts

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

Q9

Tell me about a time you had to learn something new very quickly to meet a deadline.

Adaptability & Ambiguity
Author's notes

I had a decent story here about picking up a new framework under time pressure.

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AI HintsAI Generated

Suggested Approach

Use the STAR method to structure your answer, focusing on a specific instance where you rapidly acquired a new skill or technology under time pressure. Emphasize the concrete steps you took to learn efficiently, the resources you leveraged, and the successful outcome that met or exceeded the deadline.

Pro tip: Highlight how you prioritized the most critical aspects of the new technology to deliver value quickly, and mention any trade-offs you made—this shows pragmatic decision-making valued at AWS.

1. Set the Context

Briefly describe the situation: the project, the deadline, and why learning something new was necessary. Mention the stakes and any constraints.

2. Explain Your Learning Strategy

Detail the specific approach you took to learn quickly: what resources you used (documentation, tutorials, mentors), how you prioritized topics, and how you balanced learning with doing.

3. Describe the Application

Explain how you applied the new knowledge to the project, including any challenges you faced and how you overcame them. Emphasize iterative learning and quick adjustments.

4. Highlight Collaboration and Resourcefulness

Mention how you sought help from colleagues, used internal tools, or leveraged community resources to accelerate your learning and avoid pitfalls.

5. Share the Results and Lessons Learned

Conclude with the outcome: did you meet the deadline? What was the impact? Reflect on what you learned about rapid learning and how you might apply it in the future.

Key Points to Mention

  • Specific learning techniques (e.g., focused documentation reading, hands-on experimentation, pair programming)
  • Prioritization of critical features over nice-to-haves to meet the deadline
  • Use of available resources (internal wikis, mentors, online courses) to accelerate learning
  • Effective time management and balancing learning with implementation
  • Collaboration with team members to fill knowledge gaps
  • Measurable outcome (e.g., delivered on time, positive feedback, metrics)

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