Harness Software Engineer Interview Questions + Guide in 2025

Harness is at the forefront of revolutionizing the software delivery market, empowering developers to deliver high-quality code efficiently and securely.

As a Software Engineer at Harness, you will be pivotal in designing, developing, and maintaining software that enhances the developer experience across the software delivery lifecycle. Your key responsibilities will include building scalable applications primarily using Java and Golang, developing CI/CD features, and integrating database management into the CI/CD pipeline. You'll work in a fast-paced, agile environment, utilizing iterative development cycles and short customer feedback loops. A strong understanding of data structures, algorithms, and distributed systems is crucial, as you will troubleshoot complex problems while collaborating with Site Reliability Engineers and cross-functional teams.

To thrive in this role, you should possess significant experience in developing distributed applications, familiarity with relational databases, and a passion for solving intricate technical challenges. Your ability to quickly grasp complex systems and contribute to multiple open-source technologies will be essential in our dynamic startup culture. This guide will help you prepare for your interview by providing insights into the skills and knowledge you will need to demonstrate your fit for the role at Harness.

The interview process for a Software Engineer at Harness is designed to assess both technical skills and cultural fit within the company. It typically consists of several structured rounds that focus on coding, problem-solving, and behavioral aspects.

1. Initial Phone Screen

The process begins with an initial phone screen, usually lasting around 30-45 minutes. This call is typically conducted by a recruiter who will discuss your background, the role, and the company culture. The recruiter will also gauge your interest in the position and assess your communication skills.

2. Technical Coding Rounds

Following the initial screen, candidates typically undergo two technical coding interviews. These rounds focus on data structures, algorithms, and problem-solving skills. Expect to solve coding problems in real-time, often using a collaborative coding platform. The first round may feature easier to moderate questions, while the second round tends to be more challenging, often involving complex algorithmic problems or data structure manipulations. Interviewers will be looking for clarity in your thought process, coding efficiency, and your ability to articulate your approach to problem-solving.

3. System Design Interview

In addition to coding rounds, candidates may also participate in a system design interview. This round assesses your ability to design scalable and efficient systems. You may be asked to discuss architectural decisions, trade-offs, and how you would approach building a specific feature or service. This is an opportunity to showcase your understanding of distributed systems and your experience with relevant technologies.

4. Behavioral Interview

The final round is typically a behavioral interview, which focuses on your past experiences, teamwork, and how you handle challenges. Interviewers will ask about your previous projects, how you collaborate with others, and your approach to problem-solving in a team setting. This round is crucial for assessing cultural fit within the Harness team, as they value collaboration and a positive work environment.

5. Final Review

After completing the interview rounds, there may be a final review session where the interview panel discusses your performance across all rounds. This is where they will evaluate your technical skills, problem-solving abilities, and cultural fit before making a decision.

As you prepare for your interview, it's essential to be ready for a variety of technical questions and to demonstrate your passion for software engineering and problem-solving. Next, let's delve into the specific interview questions that candidates have encountered during the process.

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

Understand the Interview Structure

Harness typically conducts a multi-round interview process, often consisting of two technical coding rounds followed by an HR round. Familiarize yourself with this structure and prepare accordingly. The first round may include easier to moderate coding questions, while the second round can be more challenging, focusing on data structures and algorithms. Knowing this will help you manage your time and expectations during the interview.

Prepare for Technical Depth

Expect complex technical questions that assess your understanding of algorithms, data structures, and system design. Be ready to explain concepts like time and space complexity, hash tables, and the differences between arrays and linked lists. Practice coding problems that require you to implement algorithms such as binary search, string manipulation, and traversing data structures. The interviewers appreciate candidates who can articulate their thought process while coding, so think out loud as you work through problems.

Showcase Your Problem-Solving Skills

Harness values candidates who can diagnose and troubleshoot complex problems in distributed computing environments. Be prepared to discuss past experiences where you successfully identified and resolved technical challenges. Use the STAR (Situation, Task, Action, Result) method to structure your responses, highlighting your analytical skills and ability to work under pressure.

Emphasize Collaboration and Communication

The interviewers at Harness are known for their friendly demeanor, which creates a welcoming environment. Use this to your advantage by engaging in a two-way conversation. Ask clarifying questions if you don’t understand something, and be open to hints or guidance from the interviewers. Demonstrating your ability to collaborate and communicate effectively will resonate well with the company culture.

Know Your Resume and Projects

Be prepared to discuss your previous work experiences and projects in detail. Highlight your contributions, the technologies you used, and the impact of your work. This is particularly important in the final HR round, where cultural fit is assessed. Make sure to connect your experiences to the role you are applying for, showcasing how your background aligns with Harness's mission and values.

Familiarize Yourself with Harness's Products

Understanding Harness's software delivery platform and its various modules (like CI/CD, Cloud Cost Management, and Feature Flags) will give you an edge. Research how these products work and think about how your skills can contribute to their development. Asking insightful questions about the products during your interview can demonstrate your genuine interest in the company and its mission.

Be Ready for Behavioral Questions

In addition to technical questions, expect standard behavioral questions that explore your past experiences and challenges. Prepare to discuss how you handle conflict, work under pressure, and adapt to change. Harness values a culture of innovation and collaboration, so emphasize your ability to work in teams and contribute positively to the company culture.

Follow Up with Gratitude

After your interview, send a thank-you email to express your appreciation for the opportunity to interview. This not only shows your professionalism but also reinforces your interest in the position. Mention specific topics discussed during the interview to personalize your message and leave a lasting impression.

By following these tips, you can approach your interview at Harness 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 Engineer interview at Harness. The interview process is designed to assess both technical skills and cultural fit, so candidates should be prepared to demonstrate their problem-solving abilities, coding proficiency, and understanding of software development principles.

Technical Skills

1. Explain the concept of time complexity and space complexity.

Understanding algorithm efficiency is crucial for a software engineer.

How to Answer

Discuss the definitions of time and space complexity, and provide examples of how they can impact software performance.

Example

“Time complexity measures the amount of time an algorithm takes to complete based on the input size, while space complexity measures the amount of memory it uses. For instance, a binary search algorithm has a time complexity of O(log n) and a space complexity of O(1), making it efficient for large datasets.”

2. What is a hash table, and when would you use it?

Hash tables are fundamental data structures in programming.

How to Answer

Define a hash table and explain its use cases, emphasizing its efficiency in data retrieval.

Example

“A hash table is a data structure that maps keys to values for highly efficient data retrieval. It is particularly useful when you need to quickly look up data, such as in caching or implementing associative arrays.”

3. Describe the difference between an array and a linked list.

This question tests your understanding of data structures.

How to Answer

Highlight the key differences in terms of memory allocation, access time, and use cases.

Example

“An array is a collection of elements stored in contiguous memory locations, allowing for fast access via indices. In contrast, a linked list consists of nodes that are not stored in contiguous memory, which allows for dynamic memory allocation but slower access times due to the need to traverse the list.”

4. Implement a binary search algorithm.

This question assesses your coding skills and understanding of algorithms.

How to Answer

Walk through the steps of the binary search algorithm, explaining how it works and its efficiency.

Example

“Binary search works by repeatedly dividing a sorted array in half. If the target value is less than the middle element, the search continues in the left half; otherwise, it continues in the right half. This results in a time complexity of O(log n).”

5. Explain the process of traversing a binary tree using in-order traversal.

Understanding tree traversal is essential for many software engineering tasks.

How to Answer

Describe the in-order traversal method and its significance.

Example

“In-order traversal visits the left subtree, the root node, and then the right subtree. This method is particularly useful for binary search trees, as it retrieves values in sorted order.”

Problem Solving

1. Given an array of integers, find the two numbers that add up to a specific target sum.

This question tests your problem-solving and coding skills.

How to Answer

Outline your approach to solving the problem, including any algorithms or data structures you would use.

Example

“I would use a hash map to store the numbers I’ve seen so far. For each number, I would check if the complement (target - current number) exists in the map. This approach has a time complexity of O(n).”

2. Reverse a string without using built-in functions.

This question evaluates your coding ability and understanding of string manipulation.

How to Answer

Explain your approach to reversing a string using loops or recursion.

Example

“I would iterate through the string from the end to the beginning, appending each character to a new string. This can also be done recursively by swapping characters from the ends towards the center.”

3. Write a function to check if a string is a palindrome.

This question assesses your understanding of string manipulation and logic.

How to Answer

Discuss how you would compare characters from the start and end of the string.

Example

“I would compare characters from both ends of the string, moving towards the center. If all corresponding characters match, the string is a palindrome. This can be done in O(n) time.”

4. Determine whether a given string is an anagram of another string.

This question tests your ability to manipulate and compare strings.

How to Answer

Explain how you would count character occurrences in both strings.

Example

“I would use a hash map to count the occurrences of each character in both strings. If the counts match for all characters, the strings are anagrams of each other.”

5. Write a function to find the factorial of a non-negative integer.

This question evaluates your understanding of recursion and iterative solutions.

How to Answer

Discuss both the recursive and iterative approaches to calculating factorial.

Example

“I can calculate the factorial recursively by multiplying the number by the factorial of the number minus one, or iteratively by using a loop to multiply the numbers from 1 to n.”

Object-Oriented Programming (OOP)

1. Explain the concepts of encapsulation, inheritance, and polymorphism.

These are fundamental principles of OOP.

How to Answer

Define each concept and provide examples of how they are used in programming.

Example

“Encapsulation is the bundling of data and methods that operate on that data within a single unit, or class. Inheritance allows a class to inherit properties and methods from another class, promoting code reuse. Polymorphism enables methods to do different things based on the object it is acting upon, allowing for flexibility in code.”

2. What is the difference between an abstract class and an interface?

This question tests your understanding of OOP design principles.

How to Answer

Discuss the key differences in terms of implementation and usage.

Example

“An abstract class can provide some method implementations and can have state, while an interface can only declare methods without implementations. A class can implement multiple interfaces but can inherit from only one abstract class.”

3. Implement a simple class in a programming language of your choice.

This question assesses your coding skills and understanding of OOP.

How to Answer

Provide a simple example of a class with properties and methods.

Example

“In Python, I would define a class ‘Car’ with properties like ‘make’ and ‘model’, and methods like ‘start’ and ‘stop’. This encapsulates the behavior and attributes of a car.”

4. Describe the SOLID principles in software design.

Understanding SOLID principles is crucial for writing maintainable code.

How to Answer

Briefly explain each principle and its importance.

Example

“SOLID stands for Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion. These principles help in creating software that is easy to maintain and extend, promoting better design practices.”

5. How do you handle exceptions in your code?

This question tests your understanding of error handling.

How to Answer

Discuss your approach to managing exceptions and ensuring code reliability.

Example

“I use try-catch blocks to handle exceptions gracefully, logging errors for debugging while ensuring that the application can continue running or fail gracefully.”