Whatnot

Software Engineer

Software EngineerL5Hard

The Software Engineer L5 interview at Whatnot is a comprehensive process designed to assess a candidate's technical proficiency, problem-solving abilities, system design skills, and cultural fit. It typically involves multiple rounds, including technical interviews, a system design interview, and a behavioral interview.

Rounds

3

Timeline

~7 days

Experience

5 - 10 yrs

Salary Range

US$140000 - US$180000

Total Duration

150 min

Overall Evaluation Criteria

Technical Skills

Problem-solving skills
Algorithmic thinking
Data structure knowledge
Code quality and efficiency

System Design

System design principles
Scalability and performance considerations
Trade-off analysis
Understanding of distributed systems

Behavioral and Cultural Fit

Communication skills
Teamwork and collaboration
Leadership potential
Adaptability and learning agility

Preparation Tips

1Review fundamental computer science concepts (data structures, algorithms, operating systems, databases).
2Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium to hard difficulty.
3Study system design principles and common patterns (e.g., load balancing, caching, databases, message queues).
4Prepare to discuss your past projects in detail, highlighting your contributions, challenges, and learnings.
5Understand Whatnot's business and products to tailor your answers.
6Practice behavioral questions using the STAR method (Situation, Task, Action, Result).
7Be ready to ask insightful questions about the role, team, and company culture.

Study Plan

1

Data Structures and Algorithms

Weeks 1-2: Data Structures & Algorithms. Practice coding.

Weeks 1-2: Focus on Data Structures and Algorithms. Cover arrays, linked lists, trees, graphs, hash tables, heaps, and common algorithms like sorting, searching, dynamic programming, and graph traversal. Practice coding these concepts on platforms like LeetCode.

2

System Design

Weeks 3-4: System Design. Study scalability & common patterns.

Weeks 3-4: Dive into System Design. Study concepts like scalability, availability, reliability, consistency, load balancing, caching strategies, database choices (SQL vs. NoSQL), message queues, and API design. Review common system design interview questions and practice designing systems.

3

Behavioral and Cultural Fit

Week 5: Behavioral Prep. Use STAR method. Research company values.

Week 5: Prepare for Behavioral and Situational Questions. Reflect on your past experiences and prepare stories using the STAR method for common behavioral questions related to teamwork, leadership, problem-solving, and handling conflict. Research Whatnot's values and culture.

4

Mock Interviews and Final Review

Week 6: Mock Interviews & Review. Refine communication.

Week 6: Mock Interviews and Review. Conduct mock interviews with peers or mentors to simulate the actual interview environment. Focus on receiving feedback and refining your communication and problem-solving approaches. Review any weak areas identified.

Commonly Asked Questions

Given a stream of data, how would you find the k most frequent elements?
Design a URL shortening service like bit.ly.
Tell me about a time you had to work with a difficult stakeholder.
How would you design a system to handle real-time chat messages for millions of users?
Describe a situation where you had to make a difficult technical decision with incomplete information.
What are the trade-offs between SQL and NoSQL databases?
How do you approach debugging a complex distributed system?
Tell me about a time you failed and what you learned from it.

Location-Based Differences

Remote/Global

Interview Focus

Deep dive into distributed systems and scalability challenges relevant to the specific region's market.Understanding of local market trends and user behavior.Ability to collaborate effectively with geographically distributed teams.

Common Questions

Discuss a challenging technical problem you solved at scale.

How would you design a real-time notification system for a social media platform?

Describe a time you had to influence a team to adopt a new technology or approach.

Tell me about a project where you had to deal with ambiguity or changing requirements.

Tips

Research common technical challenges faced by companies in this region.
Be prepared to discuss your experience with technologies prevalent in the local tech ecosystem.
Highlight your experience working in diverse and global teams.

On-site (e.g., San Francisco)

Interview Focus

Emphasis on practical application of data structures and algorithms in real-world scenarios.Understanding of software development best practices and code quality.Ability to articulate technical decisions and trade-offs clearly.

Common Questions

How would you optimize the performance of a high-traffic e-commerce website?

Describe your experience with building and scaling microservices.

Tell me about a time you disagreed with a manager or senior engineer and how you handled it.

Walk me through a complex bug you debugged and how you approached it.

Tips

Practice coding problems on platforms like LeetCode, focusing on medium to hard difficulty.
Review fundamental computer science concepts.
Prepare to discuss your past projects in detail, focusing on your contributions and the impact.

Process Timeline

1
Data Structures and Algorithms45m
2
System Design60m
3
Behavioral and Cultural Fit45m

Interview Rounds

3-step process with detailed breakdown for each round

1

Data Structures and Algorithms

Solve 1-2 coding problems focusing on data structures and algorithms.

Technical Interview (Coding)Hard
45 minSoftware Engineer

This round focuses on your core technical skills. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will assess your ability to understand the problem, devise an efficient solution, write clean code, and explain your thought process. Expect questions that test your knowledge of arrays, strings, linked lists, trees, graphs, hash maps, heaps, and various algorithmic techniques like dynamic programming and recursion.

What Interviewers Look For

Strong problem-solving skillsProficiency in data structures and algorithmsClean and efficient coding practicesAbility to communicate technical ideas

Evaluation Criteria

Correctness of the solution
Efficiency of the solution (time and space complexity)
Code clarity and organization
Ability to explain the approach and trade-offs

Questions Asked

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

ArrayDynamic Programming

Implement a function to check if a binary tree is a valid Binary Search Tree.

TreeRecursionBinary Search Tree

Preparation Tips

1Practice coding problems on platforms like LeetCode, focusing on medium to hard difficulty.
2Understand the time and space complexity of your solutions.
3Be prepared to discuss edge cases and test your code.
4Practice explaining your approach out loud.

Common Reasons for Rejection

Inability to articulate thought process clearly.
Suboptimal algorithmic solutions.
Code with significant bugs or inefficiencies.
Lack of understanding of fundamental data structures.
2

System Design

Design a scalable software system, discussing components and trade-offs.

System Design InterviewHard
60 minSenior Software Engineer / Engineering Manager

This round assesses your ability to design complex software systems. You'll be given an open-ended problem, such as designing a specific service (e.g., a social media feed, a URL shortener, a chat application). The interviewer will evaluate your approach to requirements gathering, high-level design, component design, data modeling, API design, and identifying potential bottlenecks and failure points. Focus on scalability, reliability, and maintainability.

What Interviewers Look For

Experience in designing and building large-scale systemsKnowledge of distributed systems conceptsAbility to think critically about trade-offsClear communication of complex ideas

Evaluation Criteria

Understanding of system design principles
Ability to design for scale, reliability, and availability
Knowledge of various system components (databases, caches, load balancers, message queues)
Clarity in explaining design choices and trade-offs

Questions Asked

Design a system like Twitter's news feed.

System DesignScalabilityDistributed Systems

Design a rate limiter.

System DesignConcurrencyAlgorithms

Preparation Tips

1Study common system design patterns and architectures.
2Practice designing various systems, considering different components and trade-offs.
3Be prepared to discuss your experience with specific technologies used in distributed systems.
4Think about how to handle scale, latency, and availability.

Common Reasons for Rejection

Lack of understanding of distributed system concepts.
Inability to design scalable and reliable systems.
Poor trade-off analysis.
Not considering edge cases or failure scenarios.
3

Behavioral and Cultural Fit

Discuss past experiences and how you handle situations, focusing on teamwork and values.

Behavioral InterviewMedium
45 minHiring Manager / Senior Team Member

This round focuses on your behavioral and cultural fit. You'll be asked questions about your past experiences, how you handle specific situations, your strengths and weaknesses, and your motivations. Use the STAR method (Situation, Task, Action, Result) to provide clear and concise answers with specific examples. The interviewer wants to understand how you work with others, handle challenges, and align with Whatnot's values.

What Interviewers Look For

Cultural fitCollaboration and teamwork abilitiesProblem-solving and decision-making skillsCommunication clarityPassion for the role and company

Evaluation Criteria

Alignment with company values
Teamwork and collaboration skills
Problem-solving approach in non-technical situations
Communication and interpersonal skills
Motivation and career aspirations

Questions Asked

Tell me about a time you had to deal with a conflict within your team.

BehavioralTeamworkConflict Resolution

Describe a project you are particularly proud of and your role in it.

BehavioralProject ExperienceImpact

Preparation Tips

1Prepare examples for common behavioral questions using the STAR method.
2Research Whatnot's mission, values, and culture.
3Think about your career goals and why you are interested in this role.
4Be ready to discuss your strengths and weaknesses honestly.

Common Reasons for Rejection

Lack of self-awareness.
Inability to provide specific examples.
Poor communication or interpersonal skills.
Mismatch with company values or team dynamics.

Commonly Asked DSA Questions

Frequently asked coding questions at Whatnot

View all
Group AnagramsMEDIUMWord SearchMEDIUMNumber of IslandsMEDIUMSearch a 2D Matrix IIMEDIUMValid Palindrome IIEASYSquares of a Sorted ArrayEASYRemove All Adjacent Duplicates In StringEASY