Whatnot

Software Engineer

Software EngineerL3Medium

The Software Engineer L3 interview process at Whatnot is designed to assess a candidate's foundational technical skills, problem-solving abilities, and cultural fit. It typically involves multiple rounds focusing on data structures, algorithms, system design fundamentals, and behavioral aspects.

Rounds

4

Timeline

~7 days

Experience

1 - 3 yrs

Salary Range

US$90000 - US$130000

Total Duration

135 min

Overall Evaluation Criteria

Technical Skills

Problem-solving approach
Code quality and efficiency
Understanding of data structures and algorithms
Ability to communicate technical concepts clearly

System Design Fundamentals

System design thinking
Scalability considerations
Trade-off analysis

Behavioral and Cultural Fit

Teamwork and collaboration
Communication skills
Adaptability and learning agility
Alignment with company values

Preparation Tips

1Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, graph traversal).
2Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium-difficulty problems.
3Understand basic system design concepts such as databases, caching, load balancing, and APIs.
4Prepare examples for common behavioral questions using the STAR method (Situation, Task, Action, Result).
5Research Whatnot's products, mission, and recent news.
6Prepare questions to ask the interviewer about the role, team, and company culture.

Study Plan

1

Data Structures Fundamentals

Weeks 1-2: Data Structures (Arrays, Lists, Trees, Hash Maps) & Complexity Analysis.

Weeks 1-2: Focus on core data structures like arrays, linked lists, stacks, queues, trees (binary trees, BSTs, AVL trees), and hash maps. Practice problems related to insertion, deletion, traversal, and searching for each. Understand time and space complexity analysis.

2

Algorithms and Problem Solving

Weeks 3-4: Algorithms (Sorting, Searching, DP, Graphs) & Problem Solving.

Weeks 3-4: Dive into algorithms, including sorting (quicksort, mergesort), searching (binary search), recursion, dynamic programming, and graph algorithms (BFS, DFS, Dijkstra's). Practice implementing these algorithms and solving problems that require them.

3

System Design Introduction

Week 5: System Design Basics (APIs, Databases, Caching, Load Balancing).

Week 5: Begin exploring system design. Understand concepts like client-server architecture, RESTful APIs, database choices (SQL vs. NoSQL), caching strategies, load balancing, and microservices. Practice designing simple systems like a URL shortener or a Twitter feed.

4

Behavioral and Cultural Fit

Week 6: Behavioral Preparation (STAR Method) & Company Research.

Week 6: Focus on behavioral preparation. Identify key projects and experiences that demonstrate your skills in teamwork, problem-solving, leadership, and adaptability. Prepare stories using the STAR method for common behavioral questions.

5

Final Review and Practice

Week 7: Mock Interviews, Review & Final Preparation.

Week 7: Mock interviews, review weak areas, and finalize questions for the interviewers. Ensure you are comfortable discussing your resume and past projects in detail.

Commonly Asked Questions

Given an array of integers, find the contiguous subarray with the largest sum.
Implement a function to reverse a linked list.
Design a system to shorten URLs.
Tell me about a time you faced a technical challenge and how you overcame it.
How would you design a notification system for a social media platform?
What are your strengths and weaknesses?
Describe a situation where you had to work with a difficult team member.

Location-Based Differences

Remote

Interview Focus

Adaptability to remote collaboration tools and practices.Communication clarity in a distributed environment.

Common Questions

Tell me about a challenging project you worked on.

How do you handle disagreements within a team?

Describe a time you had to learn a new technology quickly.

Tips

Ensure a stable internet connection and a quiet environment.
Be prepared to share your screen and use virtual whiteboarding tools.
Articulate your thought process clearly, as non-verbal cues might be less apparent.

On-site

Interview Focus

Collaboration and synergy within an office environment.Understanding of in-person communication dynamics.

Common Questions

What are your thoughts on our office culture?

How do you see yourself contributing to our team's in-person collaboration?

Describe your experience with pair programming.

Tips

Be prepared for whiteboard coding sessions.
Show enthusiasm for in-person team activities and discussions.
Research the company's physical office and its amenities.

Process Timeline

0
HR Screen15m
1
Data Structures and Algorithms45m
2
System Design45m
3
Behavioral and Cultural Fit30m

Interview Rounds

4-step process with detailed breakdown for each round

0

HR Screen

Initial screening to assess basic qualifications and interest.

HR / Recruiter ScreenEasy
15 minRecruiter / HR

This is typically the first or last touchpoint with the recruiting team. They will discuss your background, interest in the role, and answer any initial questions you may have about the company, the role, or the interview process. They also ensure alignment on expectations regarding compensation and career growth.

What Interviewers Look For

Enthusiasm for the role and company.Thoughtful questions from the candidate.Clear understanding of the next steps.

Evaluation Criteria

Candidate's understanding of the role and team.
Candidate's engagement and interest.
Alignment on expectations (role, growth, compensation).

Questions Asked

What are your salary expectations?

CompensationHR

Why are you interested in Whatnot?

MotivationCompany Fit

Preparation Tips

1Have your resume and key experiences ready to discuss.
2Prepare questions about the role, team, company culture, and growth opportunities.
3Be ready to discuss salary expectations if asked.
4Confirm understanding of the next steps in the process.

Common Reasons for Rejection

Lack of alignment on expectations.
Concerns about long-term fit.
Unresolved questions or concerns from the candidate.
1

Data Structures and Algorithms

Coding challenge focused on data structures and algorithms.

Technical Interview (Coding)Medium
45 minSoftware Engineer

This round focuses on assessing your core programming skills. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will evaluate your approach to problem-solving, your ability to write clean and efficient code, and your understanding of time and space complexity.

What Interviewers Look For

Ability to break down a problem.Clean and efficient code.Understanding of algorithmic concepts.Clear communication of thought process.

Evaluation Criteria

Correctness of the solution
Efficiency of the solution (time and space complexity)
Code readability and maintainability
Problem-solving approach

Questions Asked

Given a binary tree, determine if it is a valid binary search tree.

Data StructuresTreesAlgorithms

Find the kth smallest element in a sorted matrix.

AlgorithmsArraysBinary Search

Preparation Tips

1Practice coding problems on platforms like LeetCode.
2Be prepared to explain your thought process step-by-step.
3Write clean, well-commented code.
4Consider edge cases and test your solution thoroughly.

Common Reasons for Rejection

Inability to articulate thought process.
Poor code quality or efficiency.
Lack of understanding of fundamental data structures or algorithms.
2

System Design

System design problem to assess architectural thinking.

Technical Interview (System Design)Medium
45 minSenior Software Engineer / Engineering Manager

This round evaluates your ability to design and think about larger systems. You'll be given a high-level problem (e.g., design a URL shortener, design a social media feed) and asked to outline a potential solution. The focus is on your understanding of system components, scalability, and trade-offs.

What Interviewers Look For

Ability to design a system from scratch.Knowledge of common system design patterns.Understanding of scalability and performance.Ability to discuss trade-offs.

Evaluation Criteria

Understanding of system components
Ability to design scalable solutions
Consideration of trade-offs
Clarity of design explanation

Questions Asked

Design a rate limiter.

System DesignScalability

Design a system to count unique visitors to a website.

System DesignScalabilityData Processing

Preparation Tips

1Study common system design concepts (databases, caching, load balancing, APIs).
2Practice designing systems for common use cases.
3Be prepared to discuss trade-offs between different design choices.
4Ask clarifying questions to scope the problem effectively.

Common Reasons for Rejection

Inability to think about scalability.
Poor understanding of system components.
Lack of consideration for trade-offs.
3

Behavioral and Cultural Fit

Behavioral questions to assess past experiences and cultural fit.

Behavioral InterviewMedium
30 minHiring Manager / Senior Team Member

This round focuses on your past experiences and how you approach work, collaboration, and challenges. You'll be asked behavioral questions designed to understand your work style, how you handle difficult situations, and your overall fit with the team and company culture. Using the STAR method is highly recommended.

What Interviewers Look For

Evidence of teamwork and collaboration.Ability to handle conflict and challenges.Proactiveness and ownership.Enthusiasm and positive attitude.

Evaluation Criteria

Teamwork and collaboration skills
Communication clarity
Problem-solving approach in past experiences
Adaptability and learning agility
Alignment with company values

Questions Asked

Tell me about a time you failed and what you learned from it.

BehavioralLearningResilience

Describe a situation where you had to influence a decision.

BehavioralInfluenceCommunication

Preparation Tips

1Prepare specific examples using the STAR method for common behavioral questions.
2Reflect on your past projects and roles.
3Be honest and authentic in your responses.
4Show enthusiasm for the role and the company.

Common Reasons for Rejection

Poor communication skills.
Lack of collaboration or teamwork.
Inability to provide specific examples.
Poor cultural fit.

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