# L2
**Role:** Software Engineer · **Level:** SWE II
**Company:** [Samsara](https://scaleengineer.com/companies/samsara)
**Difficulty:** Medium to Hard
**Salary:** US$120000 - US$160000
**Experience:** 2 - 5
**Timeline:** ~7 days
The L2 interview for a Software Engineer (SWE II) at Samsara is a comprehensive assessment designed to evaluate a candidate's technical proficiency, problem-solving abilities, and cultural fit. This stage typically involves multiple rounds focusing on data structures, algorithms, system design, and behavioral aspects.
Canonical: https://scaleengineer.com/interviews/samsara/swe-ii-software-engineer
---
## Overall evaluation

- Technical Proficiency
- Communication and Collaboration
- Cultural Fit

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Design a system to count unique visitors to a website.
- Explain the difference between concurrency and parallelism.
- Describe a time you disagreed with a teammate and how you resolved it.
- How would you optimize a slow database query?
- Implement a function to reverse a linked list.
- Discuss the trade-offs of using a message queue in a microservices architecture.
- Tell me about a time you failed and what you learned from it.
- Design an API for a ride-sharing service.
- What are the principles of object-oriented programming?

## Preparation tips

### lists

- Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, graph traversal).
- Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium to hard difficulty.
- Study system design concepts, including scalability, availability, reliability, and common design patterns (e.g., load balancing, caching, database sharding).
- Prepare for behavioral questions by reflecting on your past experiences using the STAR method (Situation, Task, Action, Result).
- Research Samsara's products, mission, and values to understand how your skills and experience align.
- Understand the company's tech stack and be prepared to discuss your experience with relevant technologies.
- Practice mock interviews to simulate the interview environment and get feedback.

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on core data structures and algorithms. Cover arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), graphs, and hash tables. Practice common algorithms like sorting (quicksort, mergesort), searching (binary search), recursion, dynamic programming, and graph traversal (BFS, DFS). Aim to solve at least 2-3 problems per day.","shortDescription":"Weeks 1-2: Data Structures & Algorithms fundamentals. Practice 2-3 problems daily."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into system design. Study concepts like scalability, availability, reliability, consistency, load balancing, caching strategies, database design (SQL vs. NoSQL, sharding, replication), message queues, and API design. Work through common system design case studies and practice designing systems like Twitter feed, URL shortener, or a distributed cache.","shortDescription":"Weeks 3-4: System Design concepts. Study scalability, databases, caching. Practice case studies."}
- {"title":"Behavioral and Situational Questions","longDescription":"Week 5: Prepare for behavioral and situational questions. Reflect on your past projects and experiences. Use the STAR method to structure your answers for questions about teamwork, problem-solving, leadership, handling failure, and dealing with conflict. Align your answers with Samsara's values.","shortDescription":"Week 5: Behavioral questions. Use STAR method. Align with company values."}
- {"title":"Mock Interviews and Review","longDescription":"Week 6: Mock interviews and review. Conduct mock interviews with peers or mentors to practice your coding, system design, and behavioral responses. Review weak areas identified during practice and mock interviews. Ensure you are comfortable discussing your resume and past projects in detail.","shortDescription":"Week 6: Mock interviews. Review weak areas. Discuss resume."}

## Location differences

- {"location":"San Francisco Bay Area","differences":{"tips":["Familiarize yourself with common system design patterns.","Practice explaining your thought process clearly.","Be prepared to discuss trade-offs and justify your design choices.","Research Samsara's products and technologies to tailor your answers.","Highlight experience with large-scale systems if applicable."],"interviewFocus":["System design principles","Scalability and performance","Distributed systems concepts","Problem-solving under pressure","Communication of technical ideas"],"commonQuestions":["How would you design a URL shortener service?","Discuss a time you had to debug a complex production issue.","Explain the trade-offs between SQL and NoSQL databases.","Describe your experience with distributed systems.","How do you approach writing clean and maintainable code?"]}}
- {"location":"Austin, TX","differences":{"tips":["Understand the specific challenges of building software for the IoT and logistics industries.","Be ready to discuss your experience with specific cloud services.","Emphasize your ability to work effectively in a team.","Prepare examples that showcase your adaptability and learning agility.","Showcase any experience with real-time data processing or analytics."],"interviewFocus":["Cloud-native architectures","Microservices design","Data engineering and processing","Resilience and fault tolerance","Collaboration and teamwork"],"commonQuestions":["Design a system to handle real-time traffic data.","Tell me about a challenging project you worked on and how you overcame obstacles.","What are the key differences between microservices and monolithic architectures?","How do you ensure data consistency in a distributed environment?","Describe your experience with cloud platforms like AWS or GCP."]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** Medium · **Duration:** 45 min
Coding challenge focusing on data structures and algorithms.
This round focuses on your fundamental programming skills. You will be asked to solve one or two coding problems that require knowledge of data structures and algorithms. 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, sorting, searching, and dynamic programming.
**Interviewers look for:** Strong grasp of data structures and algorithms.; Ability to translate a problem into working code.; Clear communication of thought process.; Attention to detail in coding.; Ability to consider edge cases and test the solution.
**Evaluation criteria:** Correctness of the solution; Efficiency of the solution (time and space complexity); Code quality and readability; Problem-solving approach; Ability to communicate the solution
**Common rejection reasons:** Inability to solve coding problems within the given time.; Poor understanding of fundamental data structures and algorithms.; Code that is not clean, efficient, or well-tested.; Difficulty explaining thought process or solutions.; Not asking clarifying questions.
## Questions

- Given a binary tree, find its inorder traversal.
- Implement a function to find the k-th smallest element in an unsorted array.
- Write a function to check if a string is a palindrome, ignoring non-alphanumeric characters.

## Preparation tips

- Practice coding problems on platforms like LeetCode.
- Focus on understanding time and space complexity.
- Write clean, well-commented code.
- Practice explaining your solution out loud.
- Be prepared to discuss trade-offs of different approaches.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** Hard · **Duration:** 60 min
Design a scalable system. Focus on architecture, databases, and trade-offs.
This round assesses your ability to design and architect software systems. You'll be given an open-ended problem, such as designing a specific service (e.g., a URL shortener, a social media feed, a real-time analytics system). The interviewer will evaluate your approach to requirements gathering, high-level design, component breakdown, data modeling, API design, and consideration of scalability, reliability, and performance. Be prepared to justify your choices and discuss trade-offs.
**Interviewers look for:** Understanding of distributed systems concepts.; Ability to design large-scale, complex systems.; Knowledge of databases, caching, load balancing, and message queues.; Ability to articulate design decisions and trade-offs.; Pragmatic approach to problem-solving.
**Evaluation criteria:** Scalability of the design; Reliability and availability considerations; Choice of technologies and justification; Handling of edge cases and failure modes; Clarity and completeness of the design; Ability to discuss trade-offs
**Common rejection reasons:** Lack of understanding of system design principles.; Inability to design a scalable and reliable system.; Poor justification of design choices and trade-offs.; Not considering edge cases or failure scenarios.; Difficulty communicating complex system designs.
## Questions

- Design a system like Twitter's news feed.
- How would you design a rate limiter for an API?
- Design a distributed key-value store.

## Preparation tips

- Study common system design patterns and principles.
- Practice designing various systems.
- Understand trade-offs between different technologies (e.g., SQL vs. NoSQL, REST vs. gRPC).
- Think about scalability, availability, and latency.
- Be prepared to draw diagrams and explain your design clearly.

## Round 3: Behavioral and Managerial Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Behavioral questions to assess cultural fit and past experiences.
This round focuses on your behavioral and cultural fit within Samsara. You will be asked questions about your past experiences, how you handle specific situations (e.g., conflict resolution, dealing with failure, working in a team), and your motivations. The interviewer wants to understand your working style, your values, and how you contribute to a team environment. Prepare examples using the STAR method.
**Interviewers look for:** Evidence of collaboration and teamwork.; Demonstration of ownership and initiative.; Adaptability and resilience.; Alignment with Samsara's mission.; Good communication and interpersonal skills.
**Evaluation criteria:** Alignment with Samsara's culture and values.; Past experiences and accomplishments.; Problem-solving approach in non-technical situations.; Teamwork and collaboration skills.; Communication clarity and effectiveness.; Motivation and career aspirations.
**Common rejection reasons:** Lack of alignment with company values.; Poor communication or interpersonal skills.; Inability to provide specific examples using the STAR method.; Lack of self-awareness or reflection.; Negative attitude or lack of enthusiasm.
## Questions

- Tell me about a time you had to work with a difficult colleague.
- Describe a project where you took initiative beyond your defined role.
- What are your career goals for the next 3-5 years?

## Preparation tips

- Review Samsara's mission, vision, and values.
- Prepare specific examples using the STAR method for common behavioral questions.
- Be ready to discuss your strengths and weaknesses.
- Show enthusiasm for the role and the company.
- Ask thoughtful questions about the team and culture.