# Software Engineer
**Role:** Software Engineer · **Level:** L2
**Company:** [Zoox](https://scaleengineer.com/companies/zoox)
**Difficulty:** Medium
**Salary:** US$110000 - US$140000
**Experience:** 2 - 4
**Timeline:** ~7 days
The Software Engineer L2 interview at Zoox is designed to assess a candidate's foundational knowledge in computer science, problem-solving abilities, and practical coding skills. It evaluates their capacity to contribute effectively to software development projects, collaborate with a team, and demonstrate a growing understanding of software engineering principles.
Canonical: https://scaleengineer.com/interviews/zoox/l2-software-engineer
---
## Overall evaluation

- Technical Skills
- Communication & Collaboration
- Behavioral & Cultural Fit

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Implement a function to reverse a linked list.
- Explain the difference between a process and a thread.
- Describe a situation where you had to deal with a difficult stakeholder.
- How would you design a URL shortening service?
- What are the principles of object-oriented programming?
- Write a function to find the kth smallest element in an unsorted array.
- Tell me about a time you failed and what you learned from it.

## Preparation tips

### lists

- Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, graph traversal, dynamic programming).
- Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium-difficulty problems.
- Understand core computer science concepts such as operating systems, databases, and networking.
- Prepare to discuss your past projects and technical experiences in detail, focusing on your contributions and learnings.
- Brush up on object-oriented programming (OOP) principles and design patterns.
- Be ready to answer behavioral questions using the STAR method (Situation, Task, Action, Result).
- Research Zoox's mission, values, and recent projects to tailor your answers and show genuine interest.

### studyPlan

- {"title":"Data Structures","longDescription":"Weeks 1-2: Focus on Data Structures. Cover arrays, linked lists, stacks, queues, trees (binary trees, BSTs, AVL trees), heaps, and hash tables. Practice implementing these structures and solving problems related to them. Understand their time and space complexities.","shortDescription":"Weeks 1-2: Data Structures (Arrays, Lists, Trees, Hash Maps). Practice implementations and complexity analysis."}
- {"title":"Algorithms","longDescription":"Weeks 3-4: Focus on Algorithms. Cover sorting algorithms (bubble, merge, quick), searching algorithms (binary search), graph algorithms (BFS, DFS, Dijkstra's), recursion, and dynamic programming. Practice solving problems that require applying these algorithms.","shortDescription":"Weeks 3-4: Algorithms (Sorting, Searching, Graphs, DP). Practice problem-solving and complexity analysis."}
- {"title":"System Design Fundamentals","longDescription":"Week 5: System Design Fundamentals. Understand concepts like scalability, availability, reliability, load balancing, caching, and database design. Focus on designing simple systems and discussing trade-offs.","shortDescription":"Week 5: System Design Basics (Scalability, Caching, Databases). Understand core concepts."}
- {"title":"Behavioral & Project Preparation","longDescription":"Week 6: Behavioral and Project Deep Dive. Prepare to discuss your resume projects in detail. Practice answering common behavioral questions using the STAR method. Reflect on your strengths, weaknesses, and career goals.","shortDescription":"Week 6: Behavioral Questions (STAR method) & Project Review. Prepare to discuss past experiences."}
- {"title":"Mock Interviews & Final Review","longDescription":"Week 7: Mock Interviews and Review. Conduct mock interviews focusing on both technical and behavioral aspects. Review areas where you feel less confident. Familiarize yourself with Zoox's company culture and values.","shortDescription":"Week 7: Mock Interviews & Final Review. Practice and refine answers."}

## Location differences

- {"location":"San Francisco Bay Area","differences":{"tips":["Research local Zoox projects and their impact.","Understand the specific challenges and opportunities in the region."],"interviewFocus":["Adaptability to local tech ecosystem and project needs.","Understanding of specific regional market trends and user behaviors."],"commonQuestions":["Describe a challenging bug you encountered and how you debugged it.","How do you approach code reviews?","Tell me about a time you had to learn a new technology quickly."]}}
- {"location":"Remote","differences":{"tips":["Highlight experience with remote collaboration tools and practices.","Be prepared to discuss your communication style and how you handle disagreements."],"interviewFocus":["Collaboration and communication skills in a remote or hybrid environment.","Understanding of distributed systems and asynchronous communication."],"commonQuestions":["How do you ensure code quality in a distributed team?","What are your thoughts on agile methodologies in a remote setting?","Describe a situation where you had to influence a technical decision."]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** Medium · **Duration:** 45 min
Coding challenge focused on data structures and algorithms.
This round focuses on your core technical skills. You will be presented with one or two coding problems, typically involving data structures and algorithms. The interviewer will assess how you approach the problem, your thought process, your ability to write clean and efficient code, and your understanding of complexity analysis. Expect to write code in a shared editor or on a whiteboard.
**Interviewers look for:** Logical thinking and structured problem-solving.; Ability to translate a problem into code.; Attention to detail in implementation.; Understanding of basic data structures and algorithms.
**Evaluation criteria:** Problem-solving approach.; Correctness and efficiency of the solution.; Code quality and readability.; Understanding of time and space complexity.
**Common rejection reasons:** Inability to articulate thought process.; Poor coding practices (e.g., unreadable code, lack of error handling).; Fundamental misunderstanding of data structures or algorithms.
## Questions

- Given a binary tree, find its inorder traversal.
- Implement a function to check if a string is a palindrome.

## Preparation tips

- Practice coding problems on whiteboards or shared editors.
- Clearly explain your approach before you start coding.
- Test your code with edge cases.
- Discuss time and space complexity.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** Medium · **Duration:** 45 min
Design a scalable software system.
This round assesses your ability to design software systems. You'll be given an open-ended problem, such as designing a specific application or service (e.g., a URL shortener, a social media feed). The interviewer will evaluate your approach to breaking down the problem, identifying key components, considering scalability, reliability, and trade-offs, and communicating your design effectively.
**Interviewers look for:** System thinking and architectural design skills.; Knowledge of common system design patterns.; Ability to handle ambiguity and make reasoned decisions.; Understanding of distributed systems concepts.
**Evaluation criteria:** Ability to design scalable and robust systems.; Understanding of system components and interactions.; Consideration of trade-offs (e.g., consistency vs. availability).; Clarity of explanation and justification of design decisions.
**Common rejection reasons:** Difficulty in explaining design choices.; Overly complex or inefficient design.; Lack of consideration for scalability and trade-offs.
## Questions

- Design a system to count unique visitors to a website.
- How would you design a rate limiter?

## Preparation tips

- Study common system design patterns and principles.
- Practice designing various types of systems.
- Be prepared to discuss trade-offs and justify your choices.
- Think about scalability, performance, and reliability.

## Round 3: Behavioral & Manager Round
**Type:** Behavioral Interview · **Difficulty:** Easy · **Duration:** 30 min
Assess behavioral competencies and cultural fit.
This round focuses on your behavioral and cultural fit. You'll be asked questions about your past experiences, how you handle challenges, work with others, and your motivations. The interviewer wants to understand how you operate within a team and if you align with Zoox's values. Use the STAR method to structure your answers.
**Interviewers look for:** Positive attitude and enthusiasm.; Ability to work effectively in a team.; Self-awareness and reflection.; Alignment with Zoox's culture and values.
**Evaluation criteria:** Teamwork and collaboration skills.; Problem-solving approach in non-technical situations.; Adaptability and learning mindset.; Cultural fit and alignment with Zoox's values.; Motivation and career aspirations.
**Common rejection reasons:** Lack of self-awareness.; Inability to provide specific examples.; Poor alignment with company values or team dynamics.; Negative attitude or lack of enthusiasm.
## Questions

- Tell me about a time you disagreed with a teammate. How did you resolve it?
- What are your strengths and weaknesses as a software engineer?
- Why are you interested in working at Zoox?

## Preparation tips

- Prepare examples using the STAR method for common behavioral questions.
- Reflect on your strengths, weaknesses, and career goals.
- Research Zoox's company culture and values.
- Be prepared to ask thoughtful questions about the team and role.