Whatnot

Software Engineer

Software EngineerL4Medium to Hard

The Software Engineer L4 interview process at Whatnot is designed to assess a candidate's technical proficiency, problem-solving abilities, 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

3 - 7 yrs

Salary Range

US$130000 - US$180000

Total Duration

150 min

Overall Evaluation Criteria

Technical Proficiency

Technical Skills (Data Structures, Algorithms, Coding Proficiency)
Problem-Solving Abilities
System Design and Scalability Knowledge
Communication Skills
Teamwork and Collaboration
Cultural Fit
Motivation and Passion

Problem-Solving Skills

Ability to break down complex problems into smaller, manageable parts.
Logical thinking and analytical skills.
Creativity in finding solutions.
Efficiency and optimization of solutions.

System Design

Understanding of distributed systems concepts.
Ability to design scalable and reliable systems.
Knowledge of trade-offs in system design.
Experience with relevant technologies (databases, caching, messaging queues).

Communication

Clarity and conciseness in explanations.
Ability to articulate technical concepts to different audiences.
Active listening skills.
Constructive feedback delivery.

Teamwork and Culture

Demonstrated ability to work effectively in a team.
Respect for diverse perspectives.
Willingness to help and support colleagues.
Conflict resolution skills.

Preparation Tips

1Review fundamental data structures and algorithms (arrays, linked lists, trees, graphs, hash maps, sorting, searching).
2Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium and hard difficulties.
3Study system design concepts: scalability, availability, reliability, databases (SQL vs. NoSQL), caching, load balancing, message queues, APIs.
4Prepare for behavioral questions using the STAR method (Situation, Task, Action, Result).
5Research Whatnot's products, mission, and values.
6Understand common software development principles (SOLID, DRY, KISS).
7Be ready to discuss your past projects in detail, highlighting your contributions and learnings.
8Practice explaining your thought process clearly and concisely.
9Prepare thoughtful questions to ask the interviewer about the role, team, and company.

Study Plan

1

Data Structures and Algorithms

Weeks 1-2: Data Structures & Algorithms (Arrays, Trees, Graphs, Sorting, Searching, DP). Practice coding.

Weeks 1-2: Focus on Data Structures and Algorithms. Cover arrays, linked lists, stacks, queues, trees (binary trees, BSTs, AVL trees), graphs, hash tables. Practice implementing and analyzing the time and space complexity of operations. Solve problems related to searching, sorting, recursion, and dynamic programming.

2

System Design

Weeks 3-4: System Design (Scalability, Databases, Caching, Load Balancing, Messaging). Practice designing systems.

Weeks 3-4: Dive into System Design. Understand concepts like scalability, availability, reliability, consistency, latency, throughput. Study common design patterns for databases (SQL, NoSQL), caching strategies (e.g., Redis, Memcached), load balancing techniques, message queues (e.g., Kafka, RabbitMQ), and API design (RESTful). Practice designing common systems like Twitter feed, URL shortener, or a distributed cache.

3

Behavioral and Cultural Fit

Week 5: Behavioral Questions (STAR method) & Company Research. Prepare examples.

Week 5: Prepare for Behavioral and Situational Questions. Reflect on your past experiences and prepare specific examples using the STAR method for common questions related to teamwork, conflict resolution, leadership, problem-solving, and handling failure. Also, research Whatnot's company culture, values, and recent news to tailor your responses and questions.

4

Mock Interviews and Final Preparation

Week 6: Mock Interviews & Final Review. Practice communication and address weak areas.

Week 6: Mock Interviews and Review. Conduct mock interviews with peers or mentors to simulate the actual interview environment. Focus on practicing your communication skills, explaining your thought process, and receiving feedback. Review any weak areas identified during practice and mock interviews.

Commonly Asked Questions

Given an array of integers, find the contiguous subarray with the largest sum.
Design a system to handle real-time notifications for a social media platform.
Tell me about a time you had to deal with a difficult stakeholder.
How would you optimize a slow database query?
Explain the concept of eventual consistency.
Describe your experience with cloud platforms like AWS or GCP.
What are the trade-offs between microservices and a monolithic architecture?
How do you approach debugging a complex issue in a distributed system?
Tell me about a time you failed and what you learned from it.
If you were to build a recommendation engine for Whatnot, what would be your approach?

Location-Based Differences

San Francisco Bay Area

Interview Focus

Strong emphasis on data structures and algorithms.Deep dive into system design principles and scalability.Problem-solving approach and coding efficiency.Understanding of distributed systems and their trade-offs.

Common Questions

How would you design a URL shortener?

Explain the difference between a process and a thread.

Describe a challenging technical problem you solved.

How do you handle concurrency in your applications?

What are your thoughts on microservices vs. monoliths?

Tips

Practice coding problems on platforms like LeetCode, focusing on medium and hard difficulty.
Familiarize yourself with common system design patterns and trade-offs.
Be prepared to explain your thought process clearly and concisely.
Research Whatnot's tech stack and products to tailor your answers.

New York City

Interview Focus

Cultural fit and teamwork.Communication and collaboration skills.Motivation and passion for software engineering.Adaptability and learning agility.

Common Questions

Tell me about a time you disagreed with a teammate.

How do you prioritize your work when faced with multiple deadlines?

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

How do you stay updated with new technologies?

What are your career aspirations?

Tips

Prepare specific examples using the STAR method (Situation, Task, Action, Result).
Show enthusiasm for Whatnot's mission and values.
Ask thoughtful questions about the team and company culture.
Be honest and authentic in your responses.

Process Timeline

1
Coding Challenge45m
2
System Design60m
3
Behavioral and Cultural Fit45m

Interview Rounds

3-step process with detailed breakdown for each round

1

Coding Challenge

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

Technical Interview (Coding)Medium
45 minSoftware Engineer

This round focuses on your fundamental programming 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 write clean, efficient, and correct code, as well as your approach to problem-solving and your communication skills throughout the process.

What Interviewers Look For

A candidate who can translate a problem into working code.Someone who can think critically and break down problems.Clear communication of their approach.Attention to detail and edge cases.

Evaluation Criteria

Correctness of the solution.
Efficiency of the solution (time and space complexity).
Code quality and readability.
Ability to handle edge cases.
Communication of the thought process.

Questions Asked

Given a binary tree, invert the tree.

Data StructuresAlgorithmsTreesRecursion

Find the kth largest element in an unsorted array.

Data StructuresAlgorithmsArraysSortingHeaps

Preparation Tips

1Practice coding problems on platforms like LeetCode.
2Focus on understanding the time and space complexity of your solutions.
3Be prepared to explain your approach before you start coding.
4Write clean, well-commented code.
5Test your code with various inputs, including edge cases.

Common Reasons for Rejection

Inability to articulate thought process.
Poor coding practices (e.g., inefficient solutions, lack of error handling).
Failure to identify and address edge cases.
Lack of understanding of fundamental data structures and algorithms.
2

System Design

Design a scalable system based on a given prompt.

System Design InterviewHard
60 minSenior Software Engineer / Engineering Manager

This round assesses your ability to design complex, scalable, and reliable systems. You'll be given an open-ended problem (e.g., design Twitter, design a URL shortener) and expected to discuss various aspects of the system, including data storage, APIs, scalability, performance, and fault tolerance. You should be prepared to justify your design choices and discuss trade-offs.

What Interviewers Look For

A candidate who can think about high-level system architecture.Someone who understands distributed systems concepts.Ability to make informed design decisions and justify them.Consideration of various constraints and requirements.

Evaluation Criteria

Scalability of the proposed design.
Reliability and fault tolerance.
Clarity and completeness of the design.
Understanding of trade-offs.
Knowledge of relevant technologies.

Questions Asked

Design a system like TinyURL.

System DesignScalabilityDatabasesAPIs

Design a news feed system for a social media platform.

System DesignScalabilityDistributed SystemsDatabasesCaching

Preparation Tips

1Study common system design patterns and architectures.
2Understand concepts like load balancing, caching, database sharding, replication.
3Practice designing systems for scale.
4Be prepared to draw diagrams and explain your design clearly.
5Consider different types of databases (SQL vs. NoSQL) and their use cases.

Common Reasons for Rejection

Inability to design a scalable and reliable system.
Lack of understanding of fundamental system design principles.
Poor trade-off analysis.
Not considering failure scenarios or bottlenecks.
3

Behavioral and Cultural Fit

Discuss past experiences, teamwork, and cultural fit using the STAR method.

Behavioral InterviewMedium
45 minHiring Manager / Senior Team Member

This round focuses on your behavioral and situational responses. 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 personality, work style, and how you would fit into the team and company culture. Use the STAR method (Situation, Task, Action, Result) to structure your answers.

What Interviewers Look For

A candidate who aligns with Whatnot's culture.Someone who can work effectively with others.Demonstrated learning from past experiences.Passion for the role and the company.

Evaluation Criteria

Alignment with company values.
Teamwork and collaboration skills.
Problem-solving approach in past experiences.
Communication clarity.
Motivation and career goals.

Questions Asked

Tell me about a time you had a conflict with a coworker and how you resolved it.

BehavioralTeamworkConflict Resolution

Describe a challenging project you worked on and what made it challenging.

BehavioralProblem SolvingProject Management

Why are you interested in working at Whatnot?

BehavioralMotivationCompany Fit

Preparation Tips

1Prepare specific examples using the STAR method for common behavioral questions.
2Reflect on your strengths, weaknesses, and career goals.
3Show enthusiasm for Whatnot and the role.
4Be honest and authentic in your responses.
5Ask thoughtful questions about the team and culture.

Common Reasons for Rejection

Poor communication skills.
Lack of self-awareness.
Inability to provide specific examples.
Negative attitude or lack of enthusiasm.
Poor cultural fit with the team or company.

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