Calm Software Engineer Interview Questions + Guide in 2025

Calm is dedicated to enhancing mental well-being through its innovative digital solutions, including the leading app for sleep, meditation, and relaxation, serving over 150 million users worldwide.

As a Software Engineer at Calm, you will play a pivotal role in the Engineering Team, where your primary responsibility will be to design, develop, and maintain robust frontend and backend systems that support the functionality of Calm’s web applications. This role requires close collaboration with cross-functional teams, including product managers, designers, and other engineers, to ensure that the applications are not only reliable and secure but also user-friendly and aligned with Calm’s mission of supporting mental health journeys.

Key responsibilities include gathering technical requirements, writing high-quality code, implementing features with thorough testing protocols, and staying current with emerging technologies. The ideal candidate will possess experience in modern programming languages and frameworks such as JavaScript, Node.js, and React, along with a solid understanding of REST API design and microservice architecture. You should thrive in a fast-paced, agile environment, demonstrate excellent problem-solving skills, and exhibit a genuine enthusiasm for learning and collaboration.

This guide will help you prepare comprehensively for your interview at Calm, equipping you with insights into the role’s expectations and the company’s culture, ensuring you stand out as a candidate who aligns with Calm’s vision and values.

The interview process for a Software Engineer at Calm is structured to assess both technical skills and cultural fit within the team. It typically consists of several stages, each designed to evaluate different aspects of your qualifications and alignment with Calm's mission.

1. Initial Recruiter Screen

The process begins with a phone call from a recruiter, lasting about 30 minutes. This conversation serves as an introduction to the company and the role, where the recruiter will discuss your background, skills, and motivations for applying. They will also provide insights into Calm's culture and values, ensuring you understand what it means to work at the company.

2. Technical Phone Screen

Following the initial screen, candidates will undergo a technical phone interview. This session focuses on assessing your coding abilities and problem-solving skills. You may be asked to solve coding challenges or discuss your previous projects, particularly those that demonstrate your proficiency in relevant technologies such as JavaScript, Node.js, or React. Expect to clarify implementation details, as the prompts may be open-ended.

3. Virtual Onsite Interviews

Candidates who pass the technical screen will be invited to a virtual onsite interview, which typically consists of multiple rounds. These rounds may include a coding interview, a system design interview, and a behavioral interview. The coding interview will likely involve practical coding tasks, while the system design interview will assess your ability to architect scalable and efficient systems. The behavioral interview will focus on your experiences, teamwork, and how you align with Calm's values.

4. Cross-Functional Interviews

In addition to technical assessments, candidates may also participate in cross-functional interviews with team members from different departments, such as product management or UX design. These interviews aim to evaluate your ability to collaborate effectively across teams and understand the broader context of your work within the company.

Throughout the process, Calm emphasizes the importance of teamwork and cultural fit, so be prepared to discuss how you can contribute to a collaborative environment.

As you prepare for your interviews, consider the types of questions that may arise in each stage, particularly those that explore your technical expertise and your approach to problem-solving.

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

Understand the Interview Process

Calm's interview process is structured and involves multiple stages, including a recruiter phone screen, technical assessments, and several interviews with cross-functional team members. Familiarize yourself with this process and prepare accordingly. Be ready to discuss your technical skills in detail, as well as your collaborative experiences with product managers, UX designers, and other engineers. This will demonstrate your ability to work effectively in a team-oriented environment, which is highly valued at Calm.

Emphasize Team Collaboration

Calm places a significant emphasis on teamwork and collaboration. During your interviews, highlight your experiences working in cross-functional teams and how you’ve contributed to successful projects. Be prepared to discuss specific examples where you’ve collaborated with others to solve complex problems or deliver high-quality products. This will show that you align with Calm's mission of supporting mental health through teamwork and innovation.

Prepare for Technical Questions

Expect technical questions that may not follow the standard patterns you might find elsewhere. Calm's interviews may include coding challenges that focus on real-world applications, such as parsing JSON data or implementing features that enhance user experience. Brush up on relevant technologies like JavaScript, Node.js, and React, and practice coding problems that reflect the types of tasks you would encounter in the role. Additionally, be ready to clarify implementation details during coding interviews, as the prompts can be open-ended.

Showcase Your Passion for Mental Health

Given Calm's mission to support mental health, it’s beneficial to express your passion for this field during the interview. Share any personal experiences or projects that relate to mental health, wellness, or user experience. This will not only demonstrate your alignment with the company’s values but also show that you are genuinely interested in contributing to their mission.

Be Ready for Behavioral Questions

Calm's interviewers may ask behavioral questions to assess your fit within their culture. Prepare to discuss your values, work ethic, and how you handle challenges. Use the STAR (Situation, Task, Action, Result) method to structure your responses, ensuring you provide clear and concise examples that reflect your problem-solving abilities and adaptability.

Stay Engaged and Ask Insightful Questions

Throughout the interview, maintain an engaging demeanor and show enthusiasm for the role and the company. Prepare thoughtful questions that reflect your understanding of Calm's products and challenges. For instance, you might ask about the team’s approach to user feedback or how they measure the success of new features. This will demonstrate your proactive mindset and genuine interest in contributing to the team.

Reflect on Cultural Fit

While technical skills are crucial, cultural fit is equally important at Calm. Be mindful of the company’s commitment to diversity, equity, and inclusion. Reflect on how your values align with theirs and be prepared to discuss how you can contribute to a respectful and inclusive workplace. This will help you stand out as a candidate who not only possesses the necessary skills but also embodies the company’s ethos.

By following these tips and preparing thoroughly, you can approach your interview at Calm with confidence and clarity, positioning yourself as a strong candidate for the Software Engineer role. Good luck!

In this section, we’ll review the various interview questions that might be asked during a software engineering interview at Calm. The interview process will likely assess your technical skills, problem-solving abilities, and cultural fit within the team. Be prepared to discuss your experience with relevant technologies, your approach to collaboration, and how you can contribute to Calm's mission.

Technical Skills

1. Can you describe your experience with JavaScript and how you have used it in your previous projects?

This question aims to gauge your proficiency with JavaScript, a key technology for the role.

How to Answer

Discuss specific projects where you utilized JavaScript, focusing on the frameworks and libraries you used, as well as the challenges you faced and how you overcame them.

Example

“In my last project, I developed a web application using React, which allowed for dynamic user interactions. I faced challenges with state management, but I implemented Redux to streamline data flow, resulting in a more responsive user experience.”

2. How do you ensure the security and performance of the applications you develop?

Security and performance are critical in software development, especially in a health-focused company like Calm.

How to Answer

Explain your approach to writing secure code, conducting performance testing, and using monitoring tools to identify issues.

Example

“I prioritize security by following best practices such as input validation and using HTTPS. For performance, I regularly conduct load testing and utilize tools like Lighthouse to analyze and optimize the application’s performance metrics.”

3. Describe a time when you had to debug a complex issue in your code. What was your approach?

This question assesses your problem-solving skills and debugging techniques.

How to Answer

Outline the steps you took to identify the issue, the tools you used, and how you resolved it.

Example

“I encountered a memory leak in a Node.js application. I used Chrome DevTools to profile the memory usage and identified that a closure was retaining references to unused objects. I refactored the code to eliminate the closure, which resolved the issue and improved performance.”

4. What is your experience with RESTful APIs, and how have you implemented them in your projects?

Understanding RESTful APIs is essential for backend development.

How to Answer

Discuss your experience designing and consuming RESTful APIs, including any specific frameworks or tools you used.

Example

“I have designed RESTful APIs using Express.js, ensuring they adhere to REST principles. In one project, I created an API for a mobile app that allowed users to retrieve and update their profiles, implementing proper authentication and error handling.”

5. Can you explain the importance of unit testing and how you implement it in your workflow?

Unit testing is crucial for maintaining code quality and reliability.

How to Answer

Describe your approach to writing unit tests, the frameworks you use, and how you integrate testing into your development process.

Example

“I believe unit testing is vital for catching bugs early. I use Jest for testing my JavaScript code and ensure that I write tests for all new features. I also integrate testing into my CI/CD pipeline to automate the testing process before deployment.”

Collaboration and Culture Fit

1. How do you approach collaboration with cross-functional teams, such as product managers and designers?

Collaboration is key in a team-oriented environment like Calm.

How to Answer

Share your experience working with different teams, emphasizing communication and teamwork.

Example

“I regularly collaborate with product managers and designers by participating in sprint planning and design reviews. I find that maintaining open lines of communication helps align our goals and ensures that the final product meets user needs.”

2. Describe a successful project you worked on that required input from multiple stakeholders.

This question assesses your ability to work in a collaborative environment.

How to Answer

Highlight a project where you successfully gathered requirements and incorporated feedback from various stakeholders.

Example

“I worked on a project to enhance our app’s onboarding experience. I gathered input from UX designers, product managers, and customer support to identify pain points. By integrating their feedback, we improved user retention by 20%.”

3. How do you handle conflicts or disagreements within a team?

Conflict resolution is an important skill in any collaborative setting.

How to Answer

Discuss your approach to resolving conflicts, focusing on communication and finding common ground.

Example

“When conflicts arise, I prefer to address them directly by facilitating a discussion between the parties involved. I encourage everyone to share their perspectives and work together to find a solution that aligns with our project goals.”

4. What motivates you to work in the mental health space, and how do you see your role contributing to Calm's mission?

Understanding your motivation for working at Calm is important for cultural fit.

How to Answer

Express your passion for mental health and how your skills can help advance Calm’s mission.

Example

“I am passionate about mental health because I believe in the importance of well-being in our fast-paced world. As a software engineer, I see my role as crucial in creating reliable and user-friendly applications that can positively impact users’ lives.”

5. How do you stay current with new technologies and industry trends?

This question assesses your commitment to continuous learning.

How to Answer

Share your strategies for keeping up with technological advancements and how you apply new knowledge.

Example

“I regularly attend tech meetups and webinars, and I follow industry leaders on social media. I also dedicate time each week to explore new frameworks and tools, which I then share with my team to foster a culture of learning.”