Duo Security, now a part of Cisco, is renowned for its commitment to fostering secure access for companies by leveraging its innovative multi-factor authentication solutions. As of 2023, Duo Security remains a leader within the cybersecurity industry, renowned for simplifying security and enabling secure connections for workforces.

Securing a role as a Software Engineer at Duo Security promises to be both challenging and rewarding. The position necessitates a robust technical skill set, including proficiency in scripting languages, software development, and problem-solving prowess. At Duo Security, Software Engineers will have the opportunity to work on critical projects that drive the company's mission forward, directly contributing to high-impact security solutions.

Embarking on this journey with Duo Security? This guide will provide you with insights into the interview process, frequently asked questions, and helpful tips to prepare. Let’s dive in with Interview Query!

Submitting Your Application

The first step is to submit a compelling application that reflects your technical skills and interest in joining Duo Security as a software engineer. Whether you were contacted by a recruiter from Duo Security or have taken the initiative yourself, carefully review the job description and tailor your CV according to the prerequisites.

Tailoring your CV may include identifying specific keywords that the hiring manager might use to filter resumes and crafting a targeted cover letter. Furthermore, don’t forget to highlight relevant skills and mention your work experiences.

Recruiter/Hiring Manager Call Screening

If your CV happens to be among the shortlisted few, a recruiter from the Duo Security Talent Acquisition Team will make contact and verify key details like your experiences and skill level. Behavioral questions may also be a part of the screening process.

In some cases, the Duo Security hiring manager might join the screening round to answer your queries about the role and the company itself. They may also indulge in surface-level technical and behavioral discussions.

The whole recruiter call should take about 30 minutes.

Technical Virtual Interview

Successfully navigating the recruiter round will present you with an invitation for the technical screening round. Technical screening for the Duo Security software engineer role usually is conducted through virtual means, including video conference and screen sharing. Questions in this 1-hour long interview stage may revolve around Duo Security’s software systems, coding challenges, and problem-solving scenarios.

In the case of software engineering roles, coding assignments and algorithmic challenges are incorporated. Apart from these, your proficiency in data structures, system design, and debugging may also be assessed during the round.

Depending on the seniority of the position, case studies and similar real-scenario problems may also be assigned.

Onsite Interview Rounds

Following a second recruiter call outlining the next stage, you’ll be invited to attend the onsite interview loop. Multiple interview rounds, varying with the role, will be conducted during your day at the Duo Security office. Your technical prowess, including programming and system design capabilities, will be evaluated against the finalized candidates throughout these interviews.

If you were assigned take-home exercises, a presentation round may also await you during the onsite interview for the software engineer role at Duo Security.

Quick Tips For Duo Security Software Engineer Interviews

• Should contain three tips for interviewing for this specific company based on interview experiences.

Example:

You should plan to brush up on any technical skills and try as many practice interview questions and mock interviews as possible. A few tips for acing your Duo Security interview include:

• Understand Duo Security's Products: Duo Security questions are standardized and rely heavily on situational scenarios with their products. Study Duo’s range of security solutions and understand how you would personally improve or test them.
• Strong Fundamentals: Duo Security's software engineering interviews assess how well you understand coding principles and software design. Brush up on your knowledge of algorithms, data structures, and system design, given these questions can be some of the hardest to solve.
• Embody the Culture: Duo Security values innovation and a security-first mindset. Practice responding to behavioral questions with answers that touch on Duo's core values of teamwork, integrity, and customer-centricity.

Typically, interviews at Duo Security vary by role and team, but commonly Software Engineer interviews follow a fairly standardized process across these question topics.

• Create a function is_subsequence to determine if one string is a subsequence of another. Given two strings, string1 and string2, write a function is_subsequence to find out if string1 is a subsequence of string2.

• Implement a SinglyLinkedList class with methods to manipulate the list. Create a class SinglyLinkedList with methods to add and remove elements from the head and tail, check for item existence, access elements by index, and get the list's length.

• Write a function swap_node to swap nodes at given positions in a singly linked list. Given the head of a singly linked list and two positions x and y, write a function swap_node to swap the nodes at these positions using pointer manipulation, not by swapping values.

• Would a logistic model still be valid if a key variable had a data quality issue? Assume a logistic model is heavily weighted on one variable with sample data like 50.00, 100.00, 40.00, etc. If there was a data quality issue where some values lost their decimal points (e.g., 100.00 turned into 10000), would the model still be valid? Why or why not? How would you fix the model?

• How would you design a system to minimize missing or wrong orders on DoorDash? As a data scientist at DoorDash, you need to build a machine learning system to minimize missing or wrong orders placed on the app. How would you go about designing this system?

• What is the relationship between PCA and K-means clustering? Explain the relationship between Principal Component Analysis (PCA) and K-means clustering.

• How would you classify posts by topic on a large-scale social media website? You work at a social media website and want to build a system to automatically detect the topic of new posts. Given that several thousand posts are created every hour, how would you create a machine learning model to classify posts by topic at this scale?

• What are kernel methods in machine learning, and what are the requirements for a matrix to represent a kernel?

• What are kernel methods in machine learning?
• What are the requirements for a matrix to represent a kernel?
• What happens if we run a support vector machine model using a kernel that does not satisfy these requirements?

Ready to take the leap in your career with Duo Security? Dive into our comprehensive Duo Security Interview Guide for exclusive insights on what it takes to succeed at this dynamic company. We've gathered a wealth of interview questions specifically tailored for aspiring software engineers and other roles. Curious about the interview framework or the specific skills Duo Security values? We've got you covered.

At Interview Query, we provide you with the ultimate toolkit — from deep-dive guides to strategic tips — to help you ace your Duo Security interview. Don't just prepare; master your next career move with confidence.

Ready to set your career on the fast track? Explore all our company interview guides and reach out with any queries.

Best of luck with your interview!