Masterclass Software Engineer Interview Questions + Guide in 2025

Masterclass is an innovative online education platform that enables users to learn from the world's best instructors across a variety of subjects.

As a Software Engineer at Masterclass, you will play a crucial role in developing and enhancing the platform's software infrastructure, ensuring a seamless user experience for learners globally. Key responsibilities include writing clean, maintainable code, participating in code reviews, and collaborating with cross-functional teams to design and implement new features. A strong understanding of algorithms and data structures is essential, as well as proficiency in programming languages like Python and SQL. You should possess a solid grasp of unit testing principles, data manipulation techniques, and familiarity with machine learning basics.

An ideal candidate will demonstrate problem-solving capabilities, adaptability in a fast-paced environment, and a passion for creating educational experiences that resonate with users. The values of collaboration, innovation, and commitment to user satisfaction are deeply ingrained in Masterclass's business processes.

This guide will help you prepare for your interview at Masterclass by providing insight into the role's expectations and the types of questions you may encounter, ultimately giving you the confidence to showcase your skills effectively.

The interview process for a Software Engineer at Masterclass is structured to assess both technical skills and cultural fit within the company. It typically consists of several key stages:

1. Initial Recruiter Screen

The process begins with a phone interview conducted by a recruiter. This initial screen usually lasts around 30 minutes and focuses on your background, current role, and general fit for the company. Expect questions about your technical experience, particularly related to your current job and the technologies you use. The recruiter may also provide an overview of the role and the company culture, although the depth of this discussion can vary.

2. Technical Assessment

Following the recruiter screen, candidates often complete a technical assessment. This may involve a take-home coding challenge or a live coding session, where you will be asked to solve problems using relevant programming languages and tools, such as Python and SQL. The focus will be on your ability to manipulate data, implement algorithms, and demonstrate your understanding of software engineering principles.

3. Onsite Interviews

Candidates who perform well in the technical assessment are typically invited for onsite interviews. This stage usually consists of multiple rounds with various team members, including hiring managers, engineers, and possibly product managers. Each interview will cover different aspects of your skills, including coding, system design, and problem-solving. Expect to engage in discussions about your approach to unit testing, data manipulation, and any relevant machine learning concepts.

4. Final Interview

The final stage may involve a meeting with higher-level executives or team leads. This interview is often more focused on cultural fit and your alignment with the company's values. You may be asked about your experiences working in teams, your approach to collaboration, and how you handle challenges in a work environment.

Throughout the process, it’s important to remember that you are also evaluating the company. Be prepared to ask insightful questions about their approach to diversity, work-life balance, and team dynamics, as these factors are crucial for your long-term satisfaction in the role.

Now that you have an understanding of the interview process, let’s delve into the specific questions that candidates have encountered during their interviews at Masterclass.

Technical Skills and Algorithms

1. Can you explain the difference between a stack and a queue?

Understanding data structures is fundamental for a software engineer. This question assesses your grasp of basic concepts that are crucial for efficient algorithm design.

How to Answer

Discuss the definitions of both data structures, their use cases, and how they differ in terms of data retrieval and storage.

Example

“A stack is a Last In First Out (LIFO) structure, where the last element added is the first to be removed, like a stack of plates. A queue, on the other hand, is a First In First Out (FIFO) structure, where the first element added is the first to be removed, similar to a line of people waiting for service.”

2. Describe a time you optimized an algorithm. What was the original algorithm, and how did you improve it?

This question evaluates your problem-solving skills and your ability to enhance performance.

How to Answer

Provide a specific example, detailing the original algorithm, the inefficiencies you identified, and the steps you took to optimize it.

Example

“I was working on a sorting algorithm that had a time complexity of O(n^2). I analyzed the data and realized that using a quicksort algorithm would be more efficient. After implementing it, I reduced the time complexity to O(n log n), significantly improving performance for larger datasets.”

3. How do you approach unit testing in your projects?

Unit testing is essential for maintaining code quality. This question assesses your understanding of testing methodologies.

How to Answer

Explain your testing strategy, the tools you use, and how you ensure that your code is reliable and maintainable.

Example

“I prioritize unit testing by writing tests alongside my code. I use frameworks like pytest for Python, which allows me to create comprehensive test cases. This approach helps catch bugs early and ensures that new changes don’t break existing functionality.”

4. What is your experience with version control systems?

Version control is critical for collaborative software development. This question gauges your familiarity with tools like Git.

How to Answer

Discuss your experience with version control, including how you use it in team settings and any specific workflows you follow.

Example

“I have extensive experience using Git for version control. I regularly use branching strategies to manage features and bug fixes, and I’m comfortable with pull requests and code reviews to ensure code quality in collaborative projects.”

5. Can you explain the concept of Big O notation? Why is it important?

Big O notation is a key concept in algorithm analysis. This question tests your understanding of algorithm efficiency.

How to Answer

Define Big O notation and explain its significance in evaluating the performance of algorithms.

Example

“Big O notation describes the upper limit of an algorithm's time complexity, helping us understand how the runtime grows as the input size increases. It’s crucial for comparing the efficiency of different algorithms and making informed decisions about which to use in a given scenario.”

SQL and Data Manipulation

1. How would you write a SQL query to find the second highest salary from a table?

This question tests your SQL skills and ability to manipulate data effectively.

How to Answer

Outline your thought process and the SQL functions you would use to achieve the desired result.

Example

“I would use a subquery to first select the maximum salary and then find the highest salary that is less than that value. The SQL query would look like this: SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees);”

2. Can you explain the difference between INNER JOIN and LEFT JOIN?

Understanding SQL joins is essential for data retrieval. This question assesses your knowledge of relational databases.

How to Answer

Define both types of joins and provide examples of when you would use each.

Example

“An INNER JOIN returns only the rows that have matching values in both tables, while a LEFT JOIN returns all rows from the left table and the matched rows from the right table. If there’s no match, NULL values are returned for the right table’s columns.”

3. How do you optimize a slow SQL query?

This question evaluates your problem-solving skills in database management.

How to Answer

Discuss the techniques you use to identify and resolve performance issues in SQL queries.

Example

“I start by analyzing the query execution plan to identify bottlenecks. I might add indexes to frequently queried columns, rewrite the query for efficiency, or partition large tables to improve performance.”

4. What are window functions in SQL, and when would you use them?

Window functions are powerful for data analysis. This question tests your advanced SQL knowledge.

How to Answer

Explain what window functions are and provide a scenario where they would be beneficial.

Example

“Window functions perform calculations across a set of table rows related to the current row. I would use them for tasks like calculating running totals or moving averages, which require access to multiple rows without collapsing the result set.”

5. Describe a complex SQL query you wrote and the problem it solved.

This question assesses your practical experience with SQL.

How to Answer

Provide a specific example, detailing the complexity of the query and the business problem it addressed.

Example

“I wrote a complex SQL query to analyze customer purchase patterns. It involved multiple joins across several tables and used window functions to calculate the average purchase value over time. This analysis helped the marketing team tailor their campaigns based on customer behavior.”