# Software Engineer
**Role:** Software Engineer · **Level:** L3
**Company:** [Waymo](https://scaleengineer.com/companies/waymo)
**Difficulty:** Medium
**Salary:** US$90000 - US$130000
**Experience:** 0 - 3
**Timeline:** ~14 days
The Software Engineer L3 interview process at Waymo is designed to assess a candidate's foundational knowledge in computer science, problem-solving abilities, coding proficiency, and cultural fit. The process typically involves multiple rounds, including technical interviews focusing on data structures and algorithms, system design, and behavioral aspects. The goal is to identify candidates who can contribute effectively to Waymo's innovative projects in autonomous driving technology.
Canonical: https://scaleengineer.com/interviews/waymo/l3-software-engineer
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## Overall evaluation

- Technical Skills
- Soft Skills

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Design a URL shortening service.
- Tell me about a time you disagreed with a teammate. How did you handle it?
- Implement a function to reverse a linked list.
- How would you design a system to detect and prevent deadlocks in a multi-threaded environment?
- Describe a project you are particularly proud of and your role in it.
- What are the differences between processes and threads?
- How would you optimize a slow database query?
- Tell me about a time you failed. What did you learn from it?
- Design a system for real-time ride-sharing like Uber or Lyft.

## Preparation tips

### lists

- Review fundamental computer science concepts: Data Structures, Algorithms, Operating Systems, Databases, Networking.
- Practice coding problems: Focus on arrays, strings, linked lists, trees, graphs, dynamic programming, and sorting/searching algorithms.
- Study system design principles: Scalability, availability, reliability, consistency, and common design patterns.
- Prepare for behavioral questions: Use the STAR method (Situation, Task, Action, Result) to structure your answers.
- Research Waymo: Understand the company's mission, values, and the challenges in the autonomous driving industry.
- Mock interviews: Practice with peers or use online platforms to simulate the interview environment.

### studyPlan

- {"title":"Data Structures","longDescription":"Weeks 1-2: Focus on core data structures (arrays, linked lists, stacks, queues, trees, graphs, hash tables) and their common operations and time complexities. Practice basic algorithm problems related to these structures.","shortDescription":"Weeks 1-2: Data Structures & Basic Algorithms"}
- {"title":"Algorithms","longDescription":"Weeks 3-4: Dive deeper into algorithms, including sorting (quicksort, mergesort), searching (binary search), graph traversal (BFS, DFS), and dynamic programming. Solve medium-difficulty problems on platforms like LeetCode.","shortDescription":"Weeks 3-4: Advanced Algorithms & Problem Solving"}
- {"title":"System Design","longDescription":"Weeks 5-6: Study system design concepts. Learn about designing scalable web applications, databases, caching strategies, load balancing, and microservices. Practice designing common systems like Twitter feed or URL shortener.","shortDescription":"Weeks 5-6: System Design Fundamentals"}
- {"title":"Behavioral","longDescription":"Week 7: Prepare for behavioral questions. Reflect on past experiences and prepare examples using the STAR method for common questions about teamwork, challenges, failures, and successes.","shortDescription":"Week 7: Behavioral Preparation"}
- {"title":"Final Preparation","longDescription":"Week 8: Review all topics, conduct mock interviews, and research Waymo's specific technologies and challenges. Focus on areas where you feel less confident.","shortDescription":"Week 8: Final Review & Mock Interviews"}

## Location differences

- {"location":"Mountain View, CA","differences":{"tips":["Familiarize yourself with distributed systems concepts and common architectural patterns.","Be prepared to discuss your experience with cloud platforms (GCP, AWS, Azure).","Research Waymo's specific challenges and technologies in autonomous driving."],"interviewFocus":["System design principles relevant to large-scale distributed systems.","Understanding of real-time data processing and low-latency requirements.","Problem-solving in the context of autonomous vehicle software."],"commonQuestions":["How would you design a system to manage traffic light signals for a city?","Discuss a time you had to debug a complex issue. What was your approach?","Explain the trade-offs between different database types (SQL vs. NoSQL)."]}}
- {"location":"Austin, TX","differences":{"tips":["Practice coding problems on platforms like LeetCode, focusing on medium-difficulty questions.","Review fundamental computer science concepts (operating systems, networking, databases).","Prepare examples that showcase your problem-solving and debugging skills."],"interviewFocus":["Core data structures and algorithms, with an emphasis on efficiency.","Object-oriented design principles and clean code practices.","Collaboration and teamwork skills."],"commonQuestions":["Describe a challenging coding problem you solved and how you approached it.","How do you ensure the reliability and safety of software systems?","What are your thoughts on continuous integration and continuous deployment (CI/CD)?"]}}

## Round 0: HR Screen
**Type:** HR / Recruiter Screen · **Difficulty:** Easy · **Duration:** 15 min
Initial screening and discussion of logistics.
This is typically the first or last touchpoint with the recruiting team. They will discuss the role in more detail, answer any questions you have about the company culture, benefits, and compensation. They will also assess your overall interest and fit for the position and guide you through the next steps.
**Interviewers look for:** Confirmation of interest in the role and company.; Discussion of compensation expectations.; Answering any final questions the candidate may have.; Ensuring a positive candidate experience.
**Evaluation criteria:** Mutual understanding of the role and expectations.; Candidate's enthusiasm and interest.; Alignment on compensation and benefits.; Professionalism throughout the process.
**Common rejection reasons:** Lack of alignment on role expectations.; Unrealistic salary expectations.; Poor communication during the offer negotiation phase.; Concerns raised during background checks.
## Questions

- Do you have any questions for me about the role or Waymo?
- What are your salary expectations?
- Are you interviewing with other companies?

## Preparation tips

- Prepare questions about the role, team, company culture, and career growth.
- Be ready to discuss your salary expectations based on your research.
- Reiterate your interest and enthusiasm for the position.

## Round 1: Coding Round 1
**Type:** Technical Interview - Data Structures and Algorithms · **Difficulty:** Medium · **Duration:** 45 min
Coding challenge focused on data structures and algorithms.
This round focuses on assessing your core programming skills and problem-solving abilities. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will evaluate your approach, the efficiency of your solution, and the quality of your code. Be prepared to explain your thought process, discuss trade-offs, and consider edge cases.
**Interviewers look for:** A systematic approach to problem-solving.; Proficiency in at least one programming language.; Understanding of time and space complexity.; Ability to write clean, maintainable code.; Good communication skills to explain the approach.
**Evaluation criteria:** Correctness of the solution.; Efficiency of the solution (time and space complexity).; Clarity and readability of the code.; Ability to test the solution thoroughly.; Communication of the thought process.
**Common rejection reasons:** Inability to articulate thought process clearly.; Code does not compile or has significant logical errors.; Poor understanding of fundamental data structures and algorithms.; Inability to handle edge cases or optimize solutions.
## Questions

- Given a binary tree, find its inorder traversal.
- Find the kth smallest element in an unsorted array.
- Implement a function to check if a string is a palindrome.

## Preparation tips

- Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert.
- Focus on understanding the underlying data structures and algorithms.
- Practice writing code on a whiteboard or in a simple text editor without IDE assistance.
- Think out loud and communicate your approach to the interviewer.

## Round 2: System Design Round
**Type:** Technical Interview - System Design · **Difficulty:** Medium-Hard · **Duration:** 60 min
Design a scalable software system.
This round assesses your ability to design and architect software systems. You'll be given an open-ended problem (e.g., design a social media feed, a URL shortener, or a distributed cache) and expected to propose a high-level design. The interviewer will probe your design choices, ask about trade-offs, and explore potential failure scenarios and scaling strategies.
**Interviewers look for:** A structured approach to system design.; Knowledge of distributed systems principles.; Ability to identify and address potential bottlenecks.; Consideration of non-functional requirements (performance, security, etc.).; Effective communication of complex ideas.
**Evaluation criteria:** Scalability of the proposed design.; Reliability and fault tolerance.; Clarity and completeness of the design.; Understanding of trade-offs between different design choices.; Ability to handle various constraints and requirements.
**Common rejection reasons:** Inability to design a scalable and robust system.; Lack of understanding of distributed systems concepts.; Poor consideration of trade-offs and failure scenarios.; Difficulty in communicating design choices.
## Questions

- Design a system like Twitter's news feed.
- Design a rate limiter.
- Design a distributed key-value store.

## Preparation tips

- Study common system design patterns and architectures.
- Understand concepts like load balancing, caching, databases (SQL vs. NoSQL), message queues, and APIs.
- Practice designing various systems, considering scalability, availability, and performance.
- Be prepared to discuss trade-offs and justify your design decisions.

## Round 3: Behavioral Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Assessing cultural fit and past experiences.
This round focuses on your behavioral and cultural fit within Waymo. You'll be asked questions about your past experiences, teamwork, conflict resolution, and how you handle challenges. The goal is to understand your working style, motivations, and how well you align with the company's culture and values. Use the STAR method to provide specific and concise answers.
**Interviewers look for:** Examples of teamwork and collaboration.; Demonstration of leadership and initiative.; Ability to handle challenging situations and learn from mistakes.; Enthusiasm for Waymo's work in autonomous driving.; Honesty and self-awareness.
**Evaluation criteria:** Alignment with Waymo's values (e.g., safety, innovation, collaboration).; Communication and interpersonal skills.; Problem-solving approach in non-technical contexts.; Motivation and passion for Waymo's mission.; Ability to handle conflict and work in a team.
**Common rejection reasons:** Lack of self-awareness or inability to reflect on past experiences.; Poor communication or interpersonal skills.; Mismatch with company culture or values.; Inability to provide specific examples to support claims.
## Questions

- Tell me about a time you had to work with a difficult colleague.
- Describe a situation where you had to take initiative to solve a problem.
- What are your strengths and weaknesses?
- Why are you interested in Waymo?

## Preparation tips

- Prepare examples using the STAR method for common behavioral questions.
- Research Waymo's mission, values, and culture.
- Think about why you want to work at Waymo specifically.
- Be ready to discuss your strengths, weaknesses, and career goals.