# L5
**Role:** Software Engineer · **Level:** SDE II
**Company:** [Amazon](https://scaleengineer.com/companies/amazon)
**Difficulty:** Hard
**Salary:** US$130000 - US$180000
**Experience:** 4 - 8
**Timeline:** ~14 days
The L5 Software Engineer interview at Amazon (SDE II level) is a rigorous process designed to assess a candidate's technical expertise, problem-solving abilities, and alignment with Amazon's Leadership Principles. It typically involves multiple rounds focusing on data structures, algorithms, system design, and behavioral aspects.
Canonical: https://scaleengineer.com/interviews/amazon/sde-ii-software-engineer
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## Overall evaluation

- Technical and Behavioral Assessment

## Questions asked

- Design a rate limiter.
- Implement a function to find the median of a data stream.
- Given a list of strings, group anagrams.
- How would you design a distributed cache?
- Tell me about a time you failed and what you learned from it.
- Describe a complex system you designed or worked on.
- How do you handle disagreements within a team?
- Implement a function to reverse a linked list.
- Design a system to suggest friends on a social network.
- What is the difference between a process and a thread?

## Preparation tips

### lists

- Master Data Structures and Algorithms: Focus on arrays, linked lists, trees, graphs, hash maps, heaps, and sorting/searching algorithms.
- Practice System Design: Study common design patterns, distributed systems concepts (CAP theorem, consistency models), and practice designing various systems.
- Understand Amazon's Leadership Principles: Prepare STAR method (Situation, Task, Action, Result) stories for each principle.
- Coding Practice: Solve problems on platforms like LeetCode, HackerRank, focusing on optimal solutions.
- Mock Interviews: Simulate the interview environment to get feedback on your technical and communication skills.
- Review Past Projects: Be ready to discuss your contributions and technical challenges in previous roles.

### studyPlan

- {"title":"Foundational Data Structures and Algorithms","longDescription":"Weeks 1-3: Focus on foundational data structures (arrays, linked lists, stacks, queues, trees, graphs) and their common operations. Practice basic algorithms like sorting, searching, and recursion. Solve easy to medium LeetCode problems related to these topics. Begin reading about Amazon's Leadership Principles.","shortDescription":"Weeks 1-3: Data Structures & Basic Algorithms. Read LPs."}
- {"title":"Advanced Algorithms and Complexity Analysis","longDescription":"Weeks 4-6: Dive deeper into advanced data structures (heaps, tries, hash tables) and algorithms (dynamic programming, greedy algorithms, graph traversal). Focus on time and space complexity analysis. Solve medium to hard LeetCode problems. Start preparing STAR method stories for Leadership Principles.","shortDescription":"Weeks 4-6: Advanced Algorithms & Complexity. Prepare STAR stories."}
- {"title":"System Design","longDescription":"Weeks 7-9: Concentrate on System Design. Study concepts like scalability, availability, databases (SQL vs. NoSQL), caching, load balancing, message queues, and microservices. Practice designing common systems. Continue refining STAR stories and practicing behavioral questions.","shortDescription":"Weeks 7-9: System Design Fundamentals. Refine STAR stories."}
- {"title":"Intensive Practice and Mock Interviews","longDescription":"Weeks 10-12: Intensive practice. Solve a mix of problems across all topics. Conduct mock interviews focusing on both technical and behavioral aspects. Review your weak areas and reinforce your understanding of Leadership Principles. Prepare specific examples for each principle.","shortDescription":"Weeks 10-12: Mixed Practice, Mock Interviews, LP Reinforcement."}

## Location differences

- {"location":"Seattle, USA","differences":{"tips":["For Seattle/US interviews, be prepared for in-depth system design discussions and complex algorithmic problems.","Practice explaining your thought process clearly and concisely.","For international locations (e.g., India, Europe), while technical rigor is high, there might be a slightly greater emphasis on foundational data structures and algorithms, alongside behavioral questions tailored to local market nuances."],"interviewFocus":["System Design: Emphasis on scalability, availability, and distributed systems.","Data Structures & Algorithms: Deep understanding of complexity and efficient implementation.","Behavioral: Strong focus on Leadership Principles, particularly 'Customer Obsession', 'Ownership', and 'Bias for Action'."],"commonQuestions":["Design a URL shortener.","Implement a Least Recently Used (LRU) cache.","Given a binary tree, find the lowest common ancestor of two nodes.","How would you design a system to track the top K trending items?","Discuss a challenging technical problem you solved and how you approached it."]}}
- {"location":"Hyderabad, India","differences":{"tips":["For India interviews, expect a strong emphasis on coding proficiency and problem-solving under pressure.","Be ready to discuss your past projects in detail, highlighting your contributions and impact.","For Europe interviews, there might be a focus on collaborative problem-solving and communication skills, in addition to technical depth."],"interviewFocus":["System Design: Focus on trade-offs and practical implementation details.","Data Structures & Algorithms: Ability to apply concepts to solve practical problems.","Behavioral: Emphasis on 'Learn and Be Curious', 'Deliver Results', and 'Dive Deep'."],"commonQuestions":["Design a system to handle real-time notifications.","Implement a function to find the k-th smallest element in a sorted matrix.","How would you design a distributed queue?","Discuss a time you had to deal with ambiguity.","Explain the concept of eventual consistency."]}}

## Round 1: Technical Round 1: Coding
**Type:** Data Structures and Algorithms · **Difficulty:** Medium · **Duration:** 45 min
Coding problems focusing on data structures and algorithms.
This round focuses on your core data structures and algorithms knowledge. You will be asked to solve one or two coding problems, typically on a shared online editor. The interviewer will assess your ability to understand the problem, devise an efficient solution, write clean and correct code, and explain your approach. Expect questions on arrays, strings, linked lists, trees, graphs, and basic dynamic programming.
**Interviewers look for:** Ability to translate a problem into code.; Efficiency of the solution.; Clarity of explanation.; Handling of edge cases.
**Evaluation criteria:** Coding proficiency; Problem-solving approach; Understanding of data structures and algorithms; Communication of thought process
**Common rejection reasons:** Inability to write clean, working code.; Poor time complexity for solutions.; Lack of understanding of fundamental data structures and algorithms.; Inability to explain the thought process clearly.
## Questions

- Given an array of integers, find the contiguous subarray with the largest sum.
- Implement a function to check if a binary tree is a Binary Search Tree (BST).

## Preparation tips

- Practice coding on a whiteboard or shared editor.
- Focus on optimizing your solutions for time and space complexity.
- Be prepared to discuss trade-offs of different approaches.
- Practice explaining your code and logic step-by-step.

## Round 2: Technical Round 2: System Design
**Type:** System Design · **Difficulty:** Hard · **Duration:** 60 min
Design of large-scale, distributed systems.
This round assesses your ability to design large-scale, distributed systems. You'll be given an open-ended problem (e.g., design Twitter, design a URL shortener) and expected to break it down, identify requirements, propose a high-level design, and then dive deep into specific components. Focus on scalability, availability, reliability, and performance. Discuss database choices, caching strategies, API design, and potential bottlenecks.
**Interviewers look for:** Ability to design complex systems from scratch.; Understanding of distributed system components (databases, caches, load balancers, message queues).; Ability to identify and mitigate potential bottlenecks and failure points.; Clear articulation of design choices and trade-offs.
**Evaluation criteria:** System design principles; Scalability and performance considerations; Trade-off analysis; Handling of distributed systems concepts; Clarity of design and communication
**Common rejection reasons:** Inability to design a scalable and robust system.; Lack of understanding of distributed systems concepts.; Poor consideration of trade-offs.; Failure to address potential failure points and bottlenecks.
## Questions

- Design a system like TinyURL.
- Design a notification service.

## Preparation tips

- Study common system design patterns and architectures.
- Understand distributed systems concepts (CAP theorem, consistency models, consensus algorithms).
- Practice designing various systems, considering different requirements.
- Be prepared to discuss trade-offs between different design choices.

## Round 3: Behavioral Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Behavioral questions assessing alignment with Leadership Principles.
This round focuses entirely on your behavioral fit with Amazon's culture, assessed through its 16 Leadership Principles. You will be asked questions about your past experiences, focusing on how you've demonstrated these principles. Use the STAR method (Situation, Task, Action, Result) to structure your answers, providing specific examples and quantifiable results where possible.
**Interviewers look for:** Evidence of applying Leadership Principles in past work.; Ability to articulate experiences clearly and concisely using the STAR method.; Ownership, accountability, and a bias for action.; Customer obsession and a desire to learn.; Collaboration and ability to handle conflict constructively.
**Evaluation criteria:** Demonstration of Leadership Principles; Behavioral competencies; Problem-solving in past experiences; Teamwork and collaboration skills; Self-awareness and learning agility
**Common rejection reasons:** Lack of alignment with Amazon's Leadership Principles.; Inability to provide specific examples using the STAR method.; Appearing arrogant or lacking humility.; Poor communication or inability to articulate experiences effectively.
## Questions

- Tell me about a time you had to make a difficult decision. What was the outcome?
- Describe a situation where you had to influence others. How did you approach it?
- Tell me about a time you took ownership of a project or task.

## Preparation tips

- Understand each of Amazon's 16 Leadership Principles thoroughly.
- Prepare multiple STAR stories for each principle, drawing from diverse experiences.
- Practice delivering your stories concisely and impactfully.
- Be honest and authentic in your responses.

## Round 4: Hiring Manager Round
**Type:** Managerial / Fit Interview · **Difficulty:** Medium · **Duration:** 30 min
Discussion with the hiring manager about role fit and career aspirations.
This is typically the final round, often with the hiring manager. It's a chance for the manager to assess your overall fit for the team, understand your career aspirations, and answer any remaining questions you might have about the role, team, or Amazon. They will also gauge your motivation and enthusiasm for the specific opportunity.
**Interviewers look for:** Enthusiasm for the specific role and team.; Alignment of career goals with the opportunity.; Ability to ask insightful questions about the team and projects.; Overall positive attitude and potential contribution to the team.
**Evaluation criteria:** Team fit; Motivation for the role; Career aspirations; Understanding of the role and team's work; Candidate's questions
**Common rejection reasons:** Lack of alignment with the team's technical direction.; Poor cultural fit with the team.; Unrealistic salary expectations.; Lack of enthusiasm for the role or team.
## Questions

- Why are you interested in this specific role and team?
- What are your long-term career aspirations?
- Do you have any questions for me about the team or the role?

## Preparation tips

- Research the team's projects and technologies.
- Prepare thoughtful questions about the role, team dynamics, and growth opportunities.
- Reiterate your interest and suitability for the position.
- Be prepared to discuss your career goals and how this role aligns with them.