# Software Engineer
**Role:** Software Engineer · **Level:** SE 3
**Company:** [eBay](https://scaleengineer.com/companies/ebay)
**Difficulty:** Medium to Hard
**Salary:** US$130000 - US$180000
**Experience:** 3 - 7
**Timeline:** ~14 days
This interview process for a Software Engineer (SE 3) at eBay is designed to assess a candidate's technical proficiency, problem-solving skills, and cultural fit within the company. The process typically involves multiple rounds, starting with an initial HR screening, followed by technical interviews focusing on data structures, algorithms, system design, and coding, and concluding with a behavioral and managerial interview.
Canonical: https://scaleengineer.com/interviews/ebay/se-3-software-engineer
---
## Overall evaluation

- Technical Skills (Data Structures & Algorithms)
- Technical Skills (System Design)
- Behavioral and Cultural Fit
- Managerial Assessment

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Design a system to count the number of unique visitors to a website.
- Explain the difference between a process and a thread.
- How would you implement a Least Recently Used (LRU) cache?
- Describe a situation where you disagreed with a team member and how you resolved it.
- What are the trade-offs of using microservices versus a monolithic architecture?
- How do you approach debugging a complex issue in a production environment?
- Write a function to reverse a linked list.
- Design an API for a ride-sharing service.
- 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 tables) and algorithms (sorting, searching, dynamic programming, graph traversal).
- Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium to hard difficulty.
- Study system design concepts, including scalability, load balancing, caching, databases (SQL vs. NoSQL), and distributed systems.
- Prepare for behavioral questions by reflecting on your past experiences using the STAR method (Situation, Task, Action, Result).
- Understand eBay's business, products, and recent news to tailor your answers and demonstrate interest.
- Practice explaining your thought process clearly and articulating trade-offs.
- Research common interview questions for Software Engineers at your level.
- Prepare questions to ask the interviewer about the role, team, and company culture.

### 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), hash tables, and graphs. Practice common algorithms like sorting (quicksort, mergesort), searching (binary search), recursion, and dynamic programming. Aim to solve 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 API design, database choices (SQL vs. NoSQL), caching strategies, load balancing, message queues, and distributed system patterns. Work through common system design case studies and practice designing systems like Twitter's feed or a URL shortener.","shortDescription":"Weeks 3-4: System Design concepts and case studies. Focus on scalability and distributed systems."}
- {"title":"Behavioral and Managerial Preparation","longDescription":"Week 5: Prepare for behavioral and managerial rounds. Reflect on your past projects and experiences, identifying examples that showcase leadership, teamwork, problem-solving, and adaptability. Use the STAR method to structure your answers. Research eBay's company values and mission.","shortDescription":"Week 5: Behavioral and Managerial preparation. Use STAR method and research company values."}
- {"title":"Mock Interviews and Final Review","longDescription":"Week 6: Mock interviews and final review. Conduct mock interviews with peers or mentors to simulate the actual interview environment. Review your notes, practice articulating your thoughts, and refine your answers. Focus on areas where you feel less confident.","shortDescription":"Week 6: Mock interviews and final review. Practice articulating thoughts and refine answers."}

## Location differences

- {"location":"USA","differences":{"tips":["For US-based roles, be prepared for in-depth system design discussions and coding challenges.","Familiarize yourself with common distributed system patterns.","Practice explaining your thought process clearly and concisely.","Research eBay's tech stack and recent product launches."],"interviewFocus":["System Design: Emphasis on scalability, reliability, and distributed systems.","Problem-Solving: Ability to break down complex problems and propose efficient solutions.","Coding Proficiency: Clean, efficient, and well-tested code.","Behavioral: Teamwork, communication, and adaptability."],"commonQuestions":["How would you design a URL shortener service?","Explain the CAP theorem and its implications.","Describe a challenging technical problem you solved and how you approached it.","What are the trade-offs between SQL and NoSQL databases?","How do you handle concurrency in a distributed system?"]}}
- {"location":"Europe","differences":{"tips":["For European roles, expect a strong emphasis on collaborative problem-solving and practical application of skills.","Be ready to discuss your experience with specific technologies relevant to the team you're interviewing for.","Highlight your contributions to team projects and your ability to adapt to changing requirements.","Understand eBay's presence and market in Europe."],"interviewFocus":["Coding Skills: Focus on practical coding ability and understanding of core programming concepts.","Agile Methodologies: Understanding of Scrum, Kanban, and iterative development.","API Design: Knowledge of API best practices and common patterns.","Collaboration: Ability to work effectively in a team environment."],"commonQuestions":["Design an API for a social media feed.","How would you optimize a database query?","Explain the principles of RESTful API design.","Describe your experience with agile development methodologies.","What are your thoughts on microservices architecture?"]}}
- {"location":"Asia","differences":{"tips":["For Asia-based roles, expect a focus on foundational computer science principles and practical coding exercises.","Be prepared to discuss your experience with large-scale data processing and cloud infrastructure.","Showcase your ability to learn quickly and adapt to new technologies.","Understand eBay's business operations and customer base in Asia."],"interviewFocus":["Algorithmic Thinking: Strong grasp of algorithms and data structures.","Cloud Technologies: Familiarity with cloud services and their applications.","Problem Diagnosis: Ability to identify and resolve technical issues.","Code Quality: Emphasis on writing maintainable and robust code."],"commonQuestions":["How would you design a recommendation engine?","Explain the concept of Big O notation and its importance.","Describe a time you had to deal with a production issue.","What are the advantages of using a cloud platform like AWS or Azure?","How do you ensure code quality and maintainability?"]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** Medium · **Duration:** 45 min
Coding problems focusing on data structures and algorithms.
This round focuses on your fundamental computer science knowledge. You will be asked to solve coding problems that test your understanding of data structures (like arrays, linked lists, trees, hash maps) and algorithms (like sorting, searching, dynamic programming). The interviewer will assess your ability to write clean, efficient, and correct code, as well as your approach to problem-solving and handling edge cases.
**Interviewers look for:** Strong understanding of data structures and algorithms; Ability to translate a problem into code; Logical thinking and problem-solving skills; Attention to detail
**Evaluation criteria:** Correctness of the solution; Efficiency of the algorithm (time and space complexity); Code readability and maintainability; Ability to handle edge cases; Problem-solving approach
**Common rejection reasons:** Poor communication of thought process; Inability to identify and correct bugs; Inefficient or incorrect algorithmic solutions; Lack of understanding of fundamental data structures
## Questions

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

## Preparation tips

- Practice coding problems on platforms like LeetCode, focusing on medium difficulty.
- Review common data structures and algorithms.
- Be prepared to explain your thought process and the time/space complexity of your solutions.
- Practice writing code on a whiteboard or in a shared editor.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** Hard · **Duration:** 60 min
Design scalable and reliable systems.
This round assesses your ability to design complex, scalable, and reliable systems. You'll be given an open-ended problem (e.g., design Twitter's news feed, a URL shortener, or a distributed cache) and expected to discuss various aspects like data modeling, API design, scalability, performance, and fault tolerance. The interviewer wants to see how you approach ambiguity and make design decisions.
**Interviewers look for:** Experience in designing large-scale systems; Knowledge of distributed systems concepts; Ability to think critically about system design trade-offs; Clear communication of complex ideas
**Evaluation criteria:** Scalability of the proposed design; Reliability and fault tolerance; Choice of technologies and justification; Understanding of trade-offs; Ability to handle large amounts of data and traffic
**Common rejection reasons:** Inability to design scalable and reliable systems; Poor understanding of trade-offs; Lack of clarity in explaining design choices; Failure to consider failure scenarios
## Questions

- Design a distributed key-value store.
- Design a rate limiter for an API.
- How would you design a system to handle real-time notifications?

## Preparation tips

- Study common system design patterns and concepts (load balancing, caching, databases, message queues).
- Practice designing various systems, considering scalability and trade-offs.
- Be prepared to draw diagrams and explain your design choices clearly.
- Research common system design interview questions and their solutions.

## Round 3: Behavioral and Team Fit Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Assess past experiences, teamwork, and cultural fit.
This round focuses on your past experiences, behavioral traits, and how you collaborate within a team. You'll be asked questions about your strengths, weaknesses, how you handle challenges, teamwork, and your career aspirations. The interviewer uses the STAR method (Situation, Task, Action, Result) to gauge your past behavior as an indicator of future performance.
**Interviewers look for:** Evidence of teamwork and collaboration; Ability to handle conflict and challenges; Ownership and accountability for work; Enthusiasm for the role and company
**Evaluation criteria:** Communication skills; Teamwork and collaboration; Problem-solving approach in past projects; Adaptability and learning agility; Cultural fit with eBay
**Common rejection reasons:** Lack of clear communication; Inability to provide specific examples; Poor alignment with company values; Negative attitude or lack of enthusiasm
## Questions

- Tell me about a time you had to work with a difficult colleague.
- Describe a project you are particularly proud of and your role in it.
- How do you stay updated with new technologies?

## Preparation tips

- Prepare specific examples using the STAR method for common behavioral questions.
- Reflect on your strengths, weaknesses, and career goals.
- Research eBay's company culture and values.
- Be ready to discuss your contributions to past projects and how you worked with others.

## Round 4: Hiring Manager Discussion
**Type:** Managerial Interview · **Difficulty:** Medium · **Duration:** 30 min
Discuss career goals, team fit, and final alignment.
This final round is typically with the hiring manager. It's an opportunity for the manager to assess your overall fit for the team, discuss your career aspirations, and ensure your expectations align with the role and the company. You'll also have a chance to ask more in-depth questions about the team's projects, culture, and growth opportunities.
**Interviewers look for:** Motivation for the role and eBay; Understanding of the team's work; Potential for growth within the company; Cultural alignment
**Evaluation criteria:** Alignment of career goals with the role; Understanding of the team's mission; Enthusiasm and motivation; Professionalism and communication
**Common rejection reasons:** Lack of clarity on career goals; Mismatch in expectations regarding role and responsibilities; Unrealistic salary expectations; Poor understanding of the team's objectives
## Questions

- What are your long-term career goals?
- Why are you interested in working at eBay?
- What kind of work environment do you thrive in?

## Preparation tips

- Prepare thoughtful questions to ask the hiring manager.
- Reiterate your interest in the role and the company.
- Be ready to discuss your career goals and how this role fits into them.
- Ensure your understanding of the role and team responsibilities is clear.