Prepare for and practice interview questions from Calm.

Calm Interview Questions

Calm Interview Guides

Let’s say we have a table with an <code>id</code> and <code>name</code> fields. The table holds over 100 million rows and we want to sample a random row in the table without throttling the database.

Write a query to randomly sample a row from this table.

Input:

<code>big_table</code> table

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>

Write a query to randomly sample a row from a big table.

Random SQL Sample

Let’s say that your company is running a standard control and variant AB test on a feature to increase conversion rates on the landing page. The PM checks the results and finds a .04 p-value.

How would you assess the validity of the result?

Experiment Validity

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

What is a key disadvantage of the F-test when compared to multiple t-tests?

What is a key disadvantage of the F-test when compared to multiple t-tests?

Hundreds of Hypotheses

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

Calm Salaries by Position

About Calm Calm is on a mission to support everyone on every step of their mental health journey. With the #1 app for sleep, meditation and relaxation as well as a growing library of digital, evidence-based mental health programs, Calm offers trusted support for individuals and organizations alike. Our flagship consumer app provides personalized content and activities - featuring a range of experts and beloved celebrity voices - to help users manage stress, improve sleep and live mindfully. Our workplace and healthcare solutions offer a consumer-friendly approach to clinical content and HIPAA-compliant resources in order to drive positive health and business outcomes. Named a TIME100 Most Influential Company, Calm supports more than 150 million people and 3,500 organizations across seven languages and 190 countries. What We Do We build Calm's product, guide Calm's analysis, secure Calm's data, and operate the platforms that underpin it all. We're product-minded, team-oriented, and grounded in the mission of meeting everyone where they're at on their mental health journey. We work in fast-moving, small pods and as a Senior Backend Engineer you will be expected to gather technical requirements, design and publish technical specs of innovative systems, as well as own building and releasing them into production. What You'll Do The Senior Software Engineer (full stack) is a critical member of the Calm Engineering Team. In this role, you will be responsible for designing, developing, and maintaining the frontend and backend systems that power our web applications. You will work closely with a team of engineers, designers, product managers, and customers to ensure that our products are reliable, performant, and secure. Specifically, you will: <ul><li>Collaborate with stakeholders to gather requirements, define project scope, and develop technical specifications</li><li>Design, develop, and maintain frontend systems that are reliable, scalable, and secure, as well as perform backend development necessary for feature completeness.</li><li>Lead development and implementation of complex frontend features and services, collaborating cross-functionally with QA, DevOps, PMs, and client engineers to ensure smooth development and deployment process</li><li>Write high-quality, well-documented, and easily maintainable code that adheres to industry standard best-practices</li><li>Ensure high test coverage for all code, including unit and integration tests</li><li>Implement frontend features with instrumentation and monitoring to detect system errors and performance issues</li><li>Stay up-to-date on the latest frontend technologies and trends</li><li>Develop, mentor and train software engineers</li></ul> Who You Are <ul><li>Experience with the following languages/technologies/frameworks (or equivalents):</li><ul><li>Javascript/Typescript</li><li>Node.js</li><li>React/Next.js</li><li>Docker</li><li>Kubernetes</li><li>Terraform</li><li>AWS / GCP / GKE</li><li>Relational DBs / SQL</li></ul><li>Experience with responsive design</li><li>Experience with REST API-based microservices design</li><li>Proven experience working effectively in a fast-paced, agile environment as part of a collaborative team</li><li>Willingness and enthusiasm to learn new technologies and tackle challenging problems</li><li>Experience providing accurate high-level estimates based on complexity and consistently delivering on time and with quality</li><li>Consistently deliver on commitments through disciplined estimates and task breakdowns</li><li>Proficiency in writing unit and integration tests in a CI/CD environment</li><li>Excellent communication skills, with the ability to convey technical solutions to both technical and non-technical stakeholders</li><li>Provide high-quality code reviews centered on code quality and mentoring</li><li>Ability to partner with leads across products to leverage institutional knowledge to solve complex problems</li><li>Ability to work independently and as part of a team</li><li>Ability to meet deadlines and work under pressure</li></ul> Nice to Haves <ul><li>Past experience building apps in highly controlled industries, i.e., healthcare</li></ul> Minimum Requirements <ul><li>This role typically requires 8 years of related experience</li><li>BS in Computer Science, Engineering, or a related technical field</li></ul> The anticipated salary range for this position is $148,500- $241,000. The base salary range represents the low and high end of Calm's salary range for this position. Not all candidates will be eligible for the upper end of the salary range. Exact salary will ultimately depend on multiple factors, which may include the successful candidate's skills, experience, and other qualifications. This role is also eligible for equity + comprehensive benefits + 401k + flexible time off. Please note that Calm may leverage artificial intelligence technology in the application review process. Calm is committed to providing reasonable accommodations for qualified individuals with disabilities, including disabled veterans. Please contact Calm's Recruiting team if you need a reasonable accommodation, assistance completing any forms, or to otherwise participate in the application process. You can reach the Recruiting team at recruitingaccommodations@calm.com We believe that mental health is health, and every person should be considered in the discussion. That's why we're proud to be an equal opportunity workplace, committed to providing equal employment opportunities to all applicants and employees regardless of race, color, religion, national origin, age, sex, marital status, ancestry, physical or mental disability, medical condition, genetic information, military or veteran status, gender identity or expression, sexual orientation, or any other characteristic protected by applicable federal, state or local law. Calm is deeply committed to diversity, equity and inclusion. We strive to create a mindful and respectful environment where everyone can bring their authentic self to work, and experience a culture that is free of harassment, racism, and discrimination. Employment offers are contingent upon the successful completion of a background check. Roles which require access to certain types of information may also require the successful completion of a drug screening. Calm participates in e-verify. E-verify provides the federal government with your Form I-9 information to confirm that you are authorized to work in the U.S. <ul><li>Right to Work</li><li>E-Verify Participation</li></ul> #LI-Remote

Calm Interview Questions

Calm Interview Guides

Calm Interview Questions

Calm Salaries by Position

Calm Opening Jobs