Whatnot

Software Engineer

Software EngineerL6Hard

The Software Engineer L6 interview at Whatnot is a comprehensive process designed to assess a candidate's technical expertise, problem-solving abilities, system design skills, and cultural fit. The process typically involves multiple rounds, including technical interviews, a system design interview, and a behavioral interview, with a focus on practical application and real-world scenarios.

Rounds

4

Timeline

~14 days

Experience

5 - 10 yrs

Salary Range

US$170000 - US$220000

Total Duration

210 min

Overall Evaluation Criteria

Technical Skills

Technical proficiency in relevant programming languages and frameworks.
Problem-solving approach and analytical skills.
Ability to design scalable and robust systems.
Understanding of data structures and algorithms.
Code quality, efficiency, and maintainability.
Communication and collaboration skills.
Cultural fit and alignment with Whatnot's values.
Leadership potential and ability to mentor.

Communication & Collaboration

Ability to articulate thought process clearly.
Active listening and responsiveness to feedback.
Clarity in explaining complex concepts.
Enthusiasm and engagement during the interview.

Cultural Fit

Alignment with Whatnot's mission and values.
Proactiveness and ownership.
Adaptability and willingness to learn.
Teamwork and interpersonal skills.

Preparation Tips

1Review core computer science concepts: Data Structures, Algorithms, Operating Systems, Databases, Networking.
2Practice coding problems on platforms like LeetCode, HackerRank, focusing on medium to hard difficulty.
3Study system design principles: scalability, availability, reliability, consistency, CAP theorem, load balancing, caching, message queues, databases (SQL vs. NoSQL).
4Prepare for behavioral questions using the STAR method (Situation, Task, Action, Result).
5Research Whatnot's products, values, and recent news.
6Understand the specific technologies used by Whatnot's engineering teams.
7Prepare questions to ask the interviewer about the role, team, and company culture.

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 maps, heaps, sorting, searching, dynamic programming, and graph traversal algorithms. Practice implementing these and analyzing their time and space complexity.

2

System Design

Weeks 3-4: System Design principles and practice.

Weeks 3-4: Dive into System Design. Study common design patterns, architectural styles (microservices, monolithic), database design, caching strategies, message queues, load balancing, and distributed system concepts. Work through common system design problems.

3

Behavioral & Cultural Fit

Week 5: Behavioral questions and company research.

Week 5: Prepare for Behavioral and Situational Questions. Reflect on past experiences related to teamwork, problem-solving, leadership, conflict resolution, and failures. Practice articulating these using the STAR method. Research Whatnot's culture and values.

4

Mock Interviews & Refinement

Week 6: Mock interviews and final review.

Week 6: Mock Interviews and Refinement. Conduct mock interviews for both technical and behavioral rounds. Get feedback and identify areas for improvement. Review any specific technologies or domains relevant to the L6 role at Whatnot.

Commonly Asked Questions

Describe a complex system you designed or significantly contributed to. What were the challenges and how did you overcome them?
How would you design a system to handle millions of concurrent users for a live auction?
Given a scenario of a sudden traffic spike, how would you ensure the stability and performance of our platform?
Tell me about a time you disagreed with a technical decision made by your team. How did you handle it?
How do you approach debugging a production issue in a distributed system?
What are your thoughts on microservices vs. monolithic architectures for a growing e-commerce platform?
Explain the concept of eventual consistency and when it's appropriate to use.
How would you design a recommendation engine for Whatnot?
Describe your experience with performance optimization at scale.
What are the key metrics you would track for a live-streaming service?

Location-Based Differences

United States

Interview Focus

Deep understanding of distributed systems and microservices architecture.Experience with high-throughput, low-latency systems.Proficiency in at least one major cloud provider.Strong problem-solving and debugging skills in complex environments.Ability to mentor junior engineers and lead technical initiatives.

Common Questions

How would you design a real-time notification system for a platform like Whatnot?

Discuss a challenging technical problem you solved and how you approached it.

Explain the trade-offs between different database technologies for a high-traffic e-commerce site.

How do you ensure scalability and reliability in distributed systems?

Describe your experience with cloud platforms (AWS, GCP, Azure) and specific services you've used.

Tips

For US-based roles, emphasize experience with large-scale systems and cloud-native architectures.
Highlight any experience with specific technologies prevalent in the US tech scene (e.g., Kubernetes, Kafka, specific database solutions).
Be prepared to discuss your contributions to open-source projects if applicable.
Showcase leadership potential and experience in driving technical decisions.

India

Interview Focus

Strong foundation in data structures and algorithms.Experience with backend development and API design.Understanding of software development lifecycle and best practices.Ability to collaborate effectively within a team.Problem-solving skills with a focus on efficiency and resource management.

Common Questions

Design a system to handle concurrent user sessions for a live-streaming application.

How would you optimize the performance of a database query for a large dataset?

Discuss your approach to building fault-tolerant systems.

What are your strategies for ensuring code quality and maintainability?

Describe a time you had to work with a legacy system and improve it.

Tips

For international roles (e.g., India), be prepared for a strong emphasis on core computer science fundamentals and DSA.
Showcase practical coding skills and ability to write clean, efficient code.
Demonstrate a good understanding of system design principles, even if not at the scale of US-based roles.
Highlight teamwork and communication skills, as these are often highly valued.

Process Timeline

1
Coding Round 145m
2
System Design Round60m
3
Behavioral Round45m
4
Hiring Manager Round60m

Interview Rounds

4-step process with detailed breakdown for each round

1

Coding Round 1

Coding challenge focusing on data structures and algorithms.

Technical Interview (Coding)Medium
45 minSoftware Engineer (often L4/L5)

This round focuses on your fundamental coding skills. You will be asked to solve 1-2 coding problems, typically involving data structures and algorithms. The interviewer will assess your ability to write clean, efficient, and bug-free code, as well as your approach to problem-solving and your communication skills in explaining your solution.

What Interviewers Look For

Clean, efficient, and correct code.Logical and structured approach to problem-solving.Understanding of time and space complexity.Ability to communicate thought process effectively.

Evaluation Criteria

Coding proficiency
Problem-solving skills
Understanding of data structures and algorithms
Ability to explain code and approach

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 TreeRecursion

Preparation Tips

1Practice coding problems on platforms like LeetCode, focusing on medium difficulty.
2Be comfortable explaining your code and the trade-offs of your solution.
3Review common data structures and algorithms.

Common Reasons for Rejection

Inability to articulate thought process clearly.
Lack of fundamental understanding in core CS concepts.
Poor problem-solving approach.
Inability to write clean, working code.
Not meeting the bar for the specific level (L6).
2

System Design Round

Design a scalable system, focusing on architecture and trade-offs.

System Design InterviewHard
60 minSenior Software Engineer or Engineering Manager

This is a crucial round for L6 candidates. You will be asked to design a large-scale system, such as a social media feed, a URL shortener, or a real-time notification system. The interviewer will assess your ability to break down the problem, identify core components, discuss trade-offs, and design for scalability, reliability, and maintainability.

What Interviewers Look For

Ability to design complex systems from scratch.Understanding of scalability, availability, and reliability.Knowledge of various system components (databases, caches, load balancers, message queues).Ability to justify design decisions and discuss trade-offs.Consideration of failure modes and error handling.

Evaluation Criteria

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

Questions Asked

Design a system like Twitter's news feed.

System DesignScalabilityDistributed Systems

Design a URL shortening service like Bitly.

System DesignAPI DesignDatabase

Design a real-time chat application.

System DesignWebSocketsScalability

Preparation Tips

1Study system design concepts thoroughly.
2Practice designing common systems.
3Be prepared to discuss databases, caching, load balancing, and message queues.
4Think about scalability, availability, and consistency.
5Clearly articulate your design choices and justify them.

Common Reasons for Rejection

Inability to design a scalable and robust system.
Lack of understanding of distributed systems concepts.
Poor trade-off analysis.
Not considering edge cases or failure scenarios.
Difficulty in communicating design choices.
3

Behavioral Round

Assesses past behavior, teamwork, and cultural fit.

Behavioral InterviewMedium
45 minHiring Manager or Senior Team Member

This round assesses your behavioral competencies and cultural fit. You'll be asked questions about your past experiences, focusing on how you've handled specific situations related to teamwork, challenges, successes, failures, and leadership. Using the STAR method (Situation, Task, Action, Result) is highly recommended.

What Interviewers Look For

Evidence of past behavior that predicts future performance.Strong communication and interpersonal skills.Ability to work effectively in a team.Ownership and accountability.Alignment with Whatnot's values.

Evaluation Criteria

Behavioral competencies
Teamwork and collaboration
Problem-solving approach in past situations
Leadership potential
Cultural fit

Questions Asked

Tell me about a time you faced a significant technical challenge. How did you overcome it?

BehavioralProblem Solving

Describe a situation where you had a conflict with a colleague or manager. How did you resolve it?

BehavioralConflict ResolutionTeamwork

Tell me about a project you are particularly proud of and your role in it.

BehavioralAccomplishmentLeadership

How do you stay updated with new technologies and trends?

BehavioralLearningAdaptability

Preparation Tips

1Prepare examples for common behavioral questions using the STAR method.
2Reflect on your strengths, weaknesses, and career goals.
3Research Whatnot's company culture and values.
4Be honest and authentic in your responses.

Common Reasons for Rejection

Lack of alignment with company values.
Poor communication or interpersonal skills.
Inability to provide specific examples using STAR method.
Lack of self-awareness or reflection.
Negative attitude or lack of enthusiasm.
4

Hiring Manager Round

Focuses on leadership, strategic thinking, and overall fit for the L6 level.

Managerial/Hiring Manager RoundHard
60 minEngineering Manager or Director

This round, often conducted by the hiring manager or a senior leader, focuses on your overall experience, leadership potential, and strategic thinking. They will delve deeper into your past projects, technical decisions, and how you've influenced teams and technical direction. Expect questions that probe your ability to mentor, lead initiatives, and contribute to the broader engineering strategy.

What Interviewers Look For

Deep technical expertise.Proven ability to lead projects and mentor engineers.Strategic thinking and ability to influence technical direction.Experience in making high-level technical decisions.Understanding of business impact of technical choices.

Evaluation Criteria

Technical depth and breadth
Leadership and mentorship capabilities
Strategic thinking and vision
Ability to drive technical initiatives
Experience relevant to L6 responsibilities

Questions Asked

Describe a time you had to make a significant technical decision with incomplete information. What was your process?

LeadershipDecision MakingProblem Solving

How would you onboard and mentor a new engineer joining your team?

LeadershipMentorshipTeamwork

What are the biggest technical challenges you foresee for a platform like Whatnot in the next 2-3 years?

StrategyTechnical VisionIndustry Trends

Tell me about a time you had to influence stakeholders to adopt a new technology or approach.

LeadershipInfluenceCommunication

Preparation Tips

1Be prepared to discuss your career trajectory and aspirations.
2Highlight instances where you've led technical projects or mentored junior engineers.
3Think about how you've influenced technical decisions and strategy.
4Understand the challenges and opportunities facing Whatnot's engineering team.
5Prepare thoughtful questions about the team's roadmap and challenges.

Common Reasons for Rejection

Lack of alignment with the role's technical requirements.
Inability to demonstrate leadership or strategic thinking.
Poor communication of vision or strategy.
Not meeting the experience bar for L6.
Mismatch in expectations regarding role and responsibilities.

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