Chargebee Software Engineer Interview Questions + Guide in 2025

Chargebee is a leading subscription billing and revenue management platform that empowers businesses to optimize their revenue streams with innovative solutions.

As a Software Engineer at Chargebee, you will play a critical role in the development and governance of our product. Your responsibilities will encompass collaborating with product design teams to create exceptional backend technologies while establishing a robust framework for backend documentation. You will act as a subject matter expert for the backend team, guiding designers, engineers, and product managers in delivering high-quality features. A strong foundation in algorithms, data structures, and design patterns is essential, as well as proficiency in Core Java, microservices, and Spring Boot, with a solid understanding of cloud platforms. You will be expected to write high-quality code and adhere to best practices in engineering, security, and design. Additionally, your ability to build and design REST APIs and collaborate with various stakeholders across the organization will be vital for successfully launching new features.

Chargebee values curiosity, customer-centricity, and diversity, reflected in its commitment to fostering an inclusive environment where every voice is heard and empowered. This guide will help you familiarize yourself with the expectations for the Software Engineer role, enhancing your preparation for the interview process.

The interview process for a Software Engineer at Chargebee is structured to assess both technical skills and cultural fit within the company. It typically consists of five rounds, each designed to evaluate different aspects of your capabilities and experiences.

1. Initial Screening

The process begins with an initial screening, which is often conducted by a recruiter. This round focuses on understanding your background, experience, and motivation for applying to Chargebee. Expect questions about your previous roles, technical skills, and how you align with the company’s values and culture.

2. Coding Assessment

Following the initial screening, candidates are required to complete a coding assessment, usually hosted on platforms like HackerRank or HackerEarth. This round tests your proficiency in data structures and algorithms, as well as your coding skills in languages such as Java. You may be asked to solve problems related to arrays, linked lists, and other fundamental concepts.

3. Technical Interviews

The next phase consists of two technical interviews. The first technical interview typically dives deeper into your coding skills and may include discussions about your previous projects. You might be asked to explain your thought process while solving coding problems and to demonstrate your understanding of algorithms and data structures.

The second technical interview often focuses on system design and low-level design (LLD). You may be tasked with designing a system or a component, such as a file transfer system, and discussing the design patterns and technologies you would use. Questions may also cover REST API design and integration with third-party platforms.

4. Managerial Round

The fourth round is usually a managerial interview, where you will meet with a senior engineer or manager. This round assesses your problem-solving abilities, collaboration skills, and how you handle challenges in a team environment. Expect situational questions that gauge your approach to debugging, feature releases, and working with cross-functional teams.

5. HR Discussion

The final round is an HR discussion, which covers topics such as salary expectations, company culture, and your long-term career goals. This is also an opportunity for you to ask questions about the work environment, team dynamics, and any other concerns you may have.

As you prepare for your interview, it’s essential to be ready for a variety of questions that will test your technical knowledge and problem-solving skills. Here are some of the types of questions you might encounter during the interview process.

Here are some tips to help you excel in your interview.

Master the Technical Foundations

Given the emphasis on algorithms and data structures in the interview process, ensure you have a solid grasp of these concepts. Brush up on your knowledge of core algorithms, data structures like linked lists and trees, and design patterns. Practice coding problems that require you to implement these concepts, as many interviewers will expect you to demonstrate your understanding through practical examples.

Prepare for System Design Questions

Expect to face system design questions, particularly around building scalable systems and REST APIs. Familiarize yourself with microservices architecture and cloud platforms, as these are crucial for the role. Be ready to discuss your thought process in designing a system, including considerations for scalability, security, and maintainability. Practice articulating your design choices clearly and confidently.

Showcase Your Project Experience

During the technical discussions, you will likely be asked about your previous projects. Prepare to discuss your contributions in detail, focusing on the technologies you used, the challenges you faced, and how you overcame them. Highlight any experience you have with integrating third-party platforms, especially in billing and payments, as this is a valuable asset for Chargebee.

Engage with the Interviewers

Chargebee values collaboration and communication, so approach your interviews as a two-way conversation. Ask insightful questions about the team dynamics, the company culture, and the projects you might be working on. This not only shows your interest in the role but also helps you gauge if Chargebee is the right fit for you.

Emphasize Your Problem-Solving Skills

Expect to encounter coding challenges that test your problem-solving abilities. Practice coding on platforms like HackerRank or LeetCode, focusing on dynamic programming and data structure-related problems. Be prepared to explain your thought process as you solve these problems, as interviewers will be looking for clarity in your reasoning and approach.

Understand Chargebee's Culture

Chargebee prides itself on fostering an inclusive environment and values curiosity and customer-centricity. Familiarize yourself with the company's mission and values, and be prepared to discuss how your personal values align with theirs. This will help you demonstrate that you are not only a technical fit but also a cultural fit for the organization.

Follow Up with Gratitude

After your interview, send a thank-you note to your interviewers expressing your appreciation for the opportunity to interview. This small gesture can leave a positive impression and reinforce your interest in the role.

By following these tips, you will be well-prepared to showcase your skills and fit for the Software Engineer role at Chargebee. Good luck!

In this section, we’ll review the various interview questions that might be asked during a Software Engineer interview at Chargebee. The interview process will focus on your technical skills, particularly in algorithms, data structures, and backend technologies, as well as your ability to collaborate with cross-functional teams. Be prepared to demonstrate your problem-solving abilities and your understanding of software development principles.

Algorithms and Data Structures

1. Can you explain the difference between a linked list and an array? When would you use one over the other?

Understanding the strengths and weaknesses of different data structures is crucial for a software engineer.

How to Answer

Discuss the characteristics of both data structures, including memory allocation, access time, and use cases. Highlight scenarios where one might be preferred over the other.

Example

"Arrays provide fast access to elements due to their contiguous memory allocation, making them ideal for scenarios where quick lookups are necessary. However, linked lists allow for dynamic memory allocation and efficient insertions and deletions, which is beneficial when the size of the dataset is unpredictable."

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

This question assesses 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 changes you made to improve its performance.

Example

"I was working on a sorting algorithm that had a time complexity of O(n^2). I replaced it with a quicksort algorithm, which reduced the time complexity to O(n log n). This significantly improved the performance of our application, especially with larger datasets."

3. How would you implement a stack using a linked list?

This question tests your understanding of data structures and your ability to implement them.

How to Answer

Explain the concept of a stack and how it can be represented using a linked list. Discuss the operations involved, such as push and pop.

Example

"I would create a linked list where each node contains a value and a pointer to the next node. The push operation would involve adding a new node at the head of the list, while the pop operation would remove the head node and return its value."

4. What is a hash table, and how does it work?

This question evaluates your knowledge of data structures and their applications.

How to Answer

Define a hash table and explain how it uses a hash function to map keys to values, allowing for efficient data retrieval.

Example

"A hash table is a data structure that stores key-value pairs. It uses a hash function to compute an index into an array of buckets or slots, from which the desired value can be found. This allows for average-case constant time complexity for lookups."

Backend Technologies

1. Explain the concept of RESTful APIs. What are the key principles?

This question assesses your understanding of web services and API design.

How to Answer

Discuss the principles of REST, including statelessness, resource representation, and the use of standard HTTP methods.

Example

"RESTful APIs are designed around the concept of resources, which are identified by URIs. Key principles include stateless interactions, where each request from a client contains all the information needed to process it, and the use of standard HTTP methods like GET, POST, PUT, and DELETE to perform operations on resources."

2. How do you ensure the security of a REST API?

This question evaluates your knowledge of security practices in API development.

How to Answer

Discuss various security measures, such as authentication, authorization, and data validation.

Example

"I ensure API security by implementing OAuth for authentication, validating all input data to prevent injection attacks, and using HTTPS to encrypt data in transit. Additionally, I regularly review and update security protocols to address new vulnerabilities."

3. Describe your experience with microservices architecture. What are its advantages?

This question assesses your familiarity with modern software architecture.

How to Answer

Explain what microservices are and discuss their benefits, such as scalability and maintainability.

Example

"Microservices architecture involves breaking down an application into smaller, independent services that can be developed, deployed, and scaled independently. This approach enhances scalability, as each service can be scaled based on demand, and improves maintainability, as teams can work on different services without affecting the entire application."

4. What is Spring Boot, and how does it simplify Java development?

This question tests your knowledge of frameworks used in backend development.

How to Answer

Discuss the features of Spring Boot that streamline Java application development, such as auto-configuration and embedded servers.

Example

"Spring Boot simplifies Java development by providing a set of conventions and defaults that reduce the need for boilerplate code. It includes features like auto-configuration, which automatically configures the application based on the dependencies present, and embedded servers, allowing for easier deployment."

SQL and Database Management

1. How do you optimize SQL queries for performance?

This question evaluates your understanding of database management and optimization techniques.

How to Answer

Discuss various strategies for optimizing SQL queries, such as indexing, query restructuring, and analyzing execution plans.

Example

"I optimize SQL queries by creating indexes on frequently queried columns, restructuring complex queries to reduce the number of joins, and using the EXPLAIN command to analyze execution plans and identify bottlenecks."

2. Can you explain the difference between SQL and NoSQL databases?

This question assesses your knowledge of different database technologies.

How to Answer

Discuss the characteristics of SQL and NoSQL databases, including their use cases and data models.

Example

"SQL databases are relational and use structured query language for defining and manipulating data, making them suitable for applications requiring complex queries and transactions. NoSQL databases, on the other hand, are non-relational and can handle unstructured data, making them ideal for applications with large volumes of data and flexible schemas."

3. Describe a time when you had to troubleshoot a database issue. What steps did you take?

This question evaluates your problem-solving skills in a database context.

How to Answer

Provide a specific example of a database issue you encountered, the steps you took to diagnose and resolve it, and the outcome.

Example

"I encountered a performance issue where queries were taking too long to execute. I started by analyzing the slow query logs, identified missing indexes, and added them. After implementing the changes, the query performance improved significantly, reducing execution time by over 50%."

4. How do you handle data migrations in a production environment?

This question assesses your experience with database management and deployment strategies.

How to Answer

Discuss your approach to planning and executing data migrations, including testing and rollback strategies.

Example

"I handle data migrations by first creating a detailed migration plan that includes a backup of the existing data. I then test the migration in a staging environment to identify potential issues. During the actual migration, I monitor the process closely and have a rollback plan in place in case of any failures."