Mercari

Software Engineer

Software EngineerMG2Medium to Hard

Mercari is looking for a talented Software Engineer at the MG2 level to join our dynamic team. This role involves designing, developing, and maintaining scalable and high-quality software solutions that power our e-commerce platform. You will collaborate with cross-functional teams to deliver innovative features and contribute to the continuous improvement of our engineering practices.

Rounds

3

Timeline

~14 days

Experience

5 - 8 yrs

Salary Range

US$110000 - US$150000

Total Duration

150 min

Overall Evaluation Criteria

Technical Skills & Problem Solving

Technical proficiency in relevant programming languages and frameworks.
Ability to design and implement scalable and robust solutions.
Strong problem-solving and analytical skills.
Effective communication and collaboration abilities.
Understanding of software development best practices and methodologies.
Cultural fit and alignment with Mercari's values.

System Design & Architecture

System design capabilities, including scalability, reliability, and maintainability.
Experience with distributed systems and microservices architecture.
Knowledge of cloud platforms and services.
Proficiency in data structures and algorithms.
Code quality, testing, and debugging skills.

Behavioral & Cultural Fit

Behavioral competencies, such as teamwork, communication, and adaptability.
Leadership potential and ability to mentor others.
Proactiveness and ownership of tasks.
Alignment with Mercari's mission and values.

Preparation Tips

1Review core computer science concepts, including data structures, algorithms, and complexity analysis.
2Practice coding problems on platforms like LeetCode, HackerRank, or similar.
3Study system design principles and common architectural patterns.
4Prepare to discuss your past projects in detail, focusing on your contributions and technical challenges.
5Research Mercari's products, services, and engineering culture.
6Prepare questions to ask the interviewers about the role, team, and company.
7Practice behavioral questions using the STAR method (Situation, Task, Action, Result).

Study Plan

1

Data Structures & Algorithms

Weeks 1-2: DSA fundamentals and practice.

Weeks 1-2: Focus on Data Structures and Algorithms. Cover arrays, linked lists, trees, graphs, hash tables, sorting, searching, dynamic programming, and greedy algorithms. Practice problems related to each topic, aiming for optimal solutions.

2

System Design

Weeks 3-4: System Design principles and patterns.

Weeks 3-4: Dive into System Design. Study concepts like scalability, availability, reliability, load balancing, caching, databases (SQL vs. NoSQL), message queues, and API design. Work through common system design interview questions.

3

Behavioral & Situational

Week 5: Behavioral questions and STAR method.

Week 5: Prepare for Behavioral and Situational questions. Reflect on your past experiences and prepare examples using the STAR method. Understand Mercari's values and how your experiences align with them.

4

Project Review & Tech Stack

Week 6: Project deep dive and tech stack review.

Week 6: Review your projects and prepare to discuss them in detail. Brush up on specific technologies relevant to Mercari's stack (e.g., Go, Java, Python, AWS, Kubernetes). Practice mock interviews.

Commonly Asked Questions

Describe a complex system you designed or contributed to. What were the key challenges and how did you overcome them?
How would you design a URL shortening service like bit.ly?
Given a large dataset, how would you find the top K most frequent elements?
Tell me about a time you disagreed with a technical decision made by your team. How did you handle it?
How do you ensure the scalability and reliability of your code?
What are the trade-offs between different database technologies (e.g., SQL vs. NoSQL)?
Explain the concept of eventual consistency.
How would you optimize the performance of a web application?
Describe your experience with CI/CD pipelines.
What are your thoughts on microservices vs. monolithic architectures?

Location-Based Differences

Remote/Hybrid

Interview Focus

Deep understanding of distributed systems and scalability.Experience with cloud platforms (AWS, GCP, Azure).Proficiency in backend development languages (e.g., Go, Java, Python).Strong problem-solving skills in a high-traffic environment.

Common Questions

How would you handle a sudden surge in traffic on our platform?

Describe a time you had to optimize a slow-performing database query.

What are your strategies for ensuring code quality and maintainability in a large codebase?

Discuss your experience with cloud-native architectures (e.g., microservices, serverless).

Tips

Be prepared to discuss specific examples of scaling challenges you've faced.
Familiarize yourself with Mercari's tech stack and common architectural patterns.
Highlight any experience with performance tuning and optimization.
Showcase your ability to work effectively in a remote or hybrid team setting.

On-site (Tokyo)

Interview Focus

System design and architectural thinking.Problem-solving and analytical skills.Collaboration and communication within a team.Understanding of software development lifecycle and best practices.

Common Questions

How do you approach designing a new feature from scratch?

Describe a challenging technical problem you solved and your thought process.

What are your thoughts on testing strategies for microservices?

How do you stay updated with the latest industry trends and technologies?

Tips

Prepare to walk through your design process for a complex system.
Be ready to articulate your reasoning behind technical decisions.
Emphasize your ability to mentor junior engineers.
Showcase your understanding of Mercari's business domain and user needs.

Process Timeline

1
Technical Coding Round 145m
2
System Design Round60m
3
Behavioral & Cultural Fit Round45m

Interview Rounds

3-step process with detailed breakdown for each round

1

Technical Coding Round 1

Coding challenge focused on DSA.

Data Structures And Algorithms InterviewMedium
45 minSoftware Engineer

This round focuses on your fundamental programming skills. You will be asked to solve one or two coding problems that test your knowledge of data structures and algorithms. The interviewer will assess your ability to write clean, efficient, and correct code, as well as your approach to problem-solving and your communication skills.

What Interviewers Look For

Strong grasp of DSA.Clean and efficient coding practices.Problem-solving approach.Ability to communicate technical ideas.

Evaluation Criteria

Correctness of the solution.
Efficiency of the algorithm (time and space complexity).
Code clarity and readability.
Ability to explain the thought process.
Handling of edge cases.

Questions Asked

Given an array of integers, find the contiguous subarray with the largest sum.

ArrayDynamic Programming

Implement a function to reverse a linked list.

Linked List

Find the kth smallest element in a binary search tree.

TreeBinary Search Tree

Preparation Tips

1Practice coding problems regularly.
2Understand the time and space complexity of your solutions.
3Be prepared to explain your approach before you start coding.
4Test your code with various inputs, including edge cases.

Common Reasons for Rejection

Inability to articulate thought process clearly.
Lack of understanding of fundamental data structures and algorithms.
Inefficient or incorrect code implementation.
Poor time management during the coding exercise.
2

System Design Round

Design a scalable system.

System Design InterviewHard
60 minSenior Software Engineer / Engineering Manager

In this round, you will be presented with a high-level system design problem. You'll need to design a scalable and reliable system, discussing various components, their interactions, and potential bottlenecks. The focus is on your ability to think critically about system architecture, trade-offs, and how to build for scale.

What Interviewers Look For

Strong system design thinking.Knowledge of distributed systems.Ability to handle ambiguity.Pragmatic approach to problem-solving.

Evaluation Criteria

Clarity and completeness of the system design.
Scalability and performance considerations.
Reliability and fault tolerance.
Understanding of trade-offs between different design choices.
Ability to justify design decisions.

Questions Asked

Design a system to handle real-time analytics for a website.

System DesignScalabilityReal-time

Design a distributed key-value store.

System DesignDistributed SystemsDatabases

Design a notification service.

System DesignMicroservices

Preparation Tips

1Study common system design patterns.
2Practice designing large-scale systems like Twitter feed, URL shortener, etc.
3Think about scalability, availability, consistency, and latency.
4Be prepared to discuss database choices, caching strategies, and load balancing.

Common Reasons for Rejection

Inability to design a scalable and robust system.
Lack of consideration for trade-offs and constraints.
Poor understanding of distributed systems concepts.
Failure to address potential failure points.
3

Behavioral & Cultural Fit Round

Assess behavioral and cultural fit.

Behavioral InterviewMedium
45 minEngineering Manager / Senior Team Member

This round assesses your behavioral and situational competencies. You'll be asked questions about your past experiences, how you handle challenges, work in teams, and your motivations. The goal is to understand your working style, your ability to collaborate, and how you align with Mercari's culture and values.

What Interviewers Look For

Collaboration and teamwork.Ownership and accountability.Adaptability and resilience.Alignment with Mercari's culture.

Evaluation Criteria

Teamwork and collaboration skills.
Communication effectiveness.
Problem-solving approach in past projects.
Adaptability and learning agility.
Cultural fit with Mercari's values.

Questions Asked

Tell me about a time you faced a significant technical challenge. How did you approach it, and what was the outcome?

BehavioralProblem Solving

Describe a situation where you had to work with a difficult team member. How did you manage the relationship?

BehavioralTeamwork

Why are you interested in Mercari and this specific role?

BehavioralMotivation

Preparation Tips

1Prepare examples using the STAR method.
2Be honest and authentic in your responses.
3Show enthusiasm for the role and the company.
4Ask thoughtful questions about the team and culture.

Common Reasons for Rejection

Poor communication or interpersonal skills.
Lack of alignment with company values.
Inability to provide specific examples of past experiences.
Negative attitude or lack of enthusiasm.

Commonly Asked DSA Questions

Frequently asked coding questions at Mercari

View all
Count Largest GroupEASYMinimum Subsequence in Non-Increasing OrderEASYMax Difference You Can Get From Changing an IntegerMEDIUMCrawler Log FolderEASYSmallest Missing Non-negative Integer After OperationsMEDIUM