Datto, Inc. Software Engineer Interview Questions + Guide in 2025

Datto, Inc. is a leading provider of data backup, recovery, and business continuity solutions designed to help businesses protect their critical data and systems.

As a Software Engineer at Datto, you will play a crucial role in designing, developing, and maintaining software applications that support the company's innovative products and services. Key responsibilities include collaborating with cross-functional teams to analyze user needs, writing efficient and maintainable code, and participating in code reviews to uphold quality standards. A strong understanding of algorithms and data structures is essential, as you will be solving complex problems and optimizing existing solutions. Proficiency in SQL and Python will be critical for data management and application development, while familiarity with REST API integration will enhance your contributions to backend functionalities.

Ideal candidates possess a problem-solving mindset, a passion for technology, and a commitment to continuous learning. Your ability to communicate effectively and work collaboratively in a team-oriented environment aligns with Datto's emphasis on innovation and customer satisfaction.

This guide will provide you with insights and tailored questions that will help you prepare for a successful interview at Datto, ensuring you showcase your technical abilities and cultural fit within the company.

The interview process for a Software Engineer at Datto, Inc. is structured to assess both technical skills and cultural fit within the company. It typically consists of several key stages:

1. Initial Phone Screen

The process begins with a phone interview, usually conducted by a recruiter or HR representative. This initial conversation lasts about 30 minutes and focuses on your background, experiences, and motivations for applying to Datto. Expect a mix of technical and behavioral questions, as well as an overview of the interview process itself.

2. Coding Assessment

Following the phone screen, candidates are often required to complete a coding assessment. This may be a take-home assignment or an online coding test, where you will be asked to solve algorithmic problems and demonstrate your programming skills. The assessment typically includes tasks such as implementing database connections, parsing JSON, and writing functions in languages like Python or Java. Be prepared for questions that require you to explain your design decisions and coding approach.

3. Technical Interviews

Candidates who perform well in the coding assessment will move on to one or more technical interviews. These interviews are usually conducted by staff engineers and focus on evaluating your understanding of software design principles, algorithms, and data structures. Expect to discuss your past projects and experiences in detail, as well as tackle technical questions that may involve problem-solving and coding on the spot.

4. Behavioral Interviews

In addition to technical assessments, there will be behavioral interviews to assess your cultural fit within the team and the company. These interviews may involve discussions about teamwork, conflict resolution, and your approach to challenges in a work environment. Interviewers will be interested in understanding how you align with Datto's values and work culture.

5. Final Interview

The final stage may involve a wrap-up interview with a manager or team lead, where you will discuss your overall fit for the role and the team. This is also an opportunity for you to ask any remaining questions about the company, team dynamics, and expectations.

Throughout the process, communication with the recruiter is emphasized, ensuring that candidates are kept informed and supported.

Now that you have an understanding of the interview process, let's delve into the specific questions that candidates have encountered during their interviews.

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

Understand the Interview Process

Familiarize yourself with the structure of the interview process at Datto. It typically begins with a recruiter call, followed by a technical assessment, and culminates in interviews with team members. Knowing this will help you prepare for each stage effectively. Be ready for a mix of behavioral and technical questions, as well as coding tests that may require you to demonstrate your problem-solving skills in real-time.

Prepare for Technical Assessments

Given the emphasis on algorithms and SQL, ensure you are well-versed in these areas. Practice coding problems that involve data structures and algorithms, as well as SQL queries. You may encounter questions that require you to design a service or solve a problem, so be prepared to articulate your thought process and design principles clearly. Familiarize yourself with REST APIs and JSON parsing, as these are common topics in coding tests.

Brush Up on Behavioral Questions

Datto places importance on cultural fit, so be prepared to discuss your past experiences and how they align with the company’s values. Reflect on your previous work, challenges you've faced, and how you’ve contributed to team success. Be ready to answer questions about why you want to work at Datto and how you can add value to their team.

Practice Coding Under Pressure

Many candidates have noted that the coding tests can be challenging, often requiring you to think on your feet. Simulate the interview environment by practicing coding problems with a timer. This will help you manage your time effectively during the actual test. Additionally, be prepared for questions that may seem straightforward but have hidden complexities, so read the problem statements carefully.

Communicate Clearly and Confidently

During the interviews, especially the technical ones, articulate your thought process as you work through problems. Interviewers appreciate candidates who can explain their reasoning and approach, even if they don’t arrive at the correct solution. This demonstrates your problem-solving skills and ability to communicate effectively with team members.

Stay Engaged and Ask Questions

Show your interest in the role and the company by asking insightful questions during your interviews. Inquire about the team dynamics, current projects, and the technologies they use. This not only demonstrates your enthusiasm but also helps you gauge if Datto is the right fit for you.

Be Prepared for a Multi-Faceted Interview

Expect to engage with multiple interviewers, as the process may involve several rounds with different team members. Each interviewer may focus on different aspects of your skills and experiences, so be adaptable and ready to showcase your strengths in various contexts.

Follow Up Professionally

After your interviews, consider sending a thank-you email to express your appreciation for the opportunity to interview. This is a chance to reiterate your interest in the position and reflect on any key points discussed during the interview that you found particularly engaging.

By following these tips and preparing thoroughly, you can approach your interview at Datto with confidence and clarity, increasing your chances of success. Good luck!

In this section, we’ll review the various interview questions that might be asked during a Software Engineer interview at Datto, Inc. The interview process will likely assess your technical skills, problem-solving abilities, and cultural fit within the team. Be prepared to demonstrate your knowledge in algorithms, SQL, and programming languages, as well as your understanding of software design principles.

Algorithms

1. Can you explain the difference between a stack and a queue?

Understanding data structures is crucial for software engineering roles.

How to Answer

Discuss the fundamental differences in how data is stored and accessed in both structures, emphasizing their use cases.

Example

“A stack follows a Last In First Out (LIFO) principle, meaning the last element added is the first to be removed, which is useful for scenarios like function calls. In contrast, a queue operates on a First In First Out (FIFO) basis, making it ideal for tasks like print job management where the first job submitted should be the first to be processed.”

2. How would you approach solving a problem where you need to find the shortest path in a graph?

This question tests your problem-solving and algorithmic thinking.

How to Answer

Mention algorithms like Dijkstra's or A* and explain when you would use each.

Example

“To find the shortest path in a graph, I would typically use Dijkstra's algorithm if all edges have non-negative weights. It efficiently finds the shortest path from a source node to all other nodes by exploring the nearest unvisited node first.”

3. Describe a time you optimized an algorithm. What was the problem and what was the outcome?

This question assesses your practical experience with algorithms.

How to Answer

Provide a specific example, detailing the original algorithm, the changes you made, and the results.

Example

“I was tasked with optimizing a sorting algorithm that was running in O(n^2) time. I replaced it with a quicksort implementation, which reduced the time complexity to O(n log n). This change improved the performance of our application significantly, especially with larger datasets.”

4. What is the time complexity of a binary search?

This question tests your understanding of algorithm efficiency.

How to Answer

Explain the concept of time complexity and how it applies to binary search.

Example

“The time complexity of a binary search is O(log n) because it divides the search interval in half with each step, making it very efficient for sorted arrays.”

5. How would you implement a function to check if a string is a palindrome?

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

How to Answer

Outline your thought process and provide a simple implementation.

Example

“I would iterate through the string from both ends towards the center, comparing characters. If all corresponding characters match, the string is a palindrome. Here’s a simple implementation in Python: I would use two pointers, one starting at the beginning and the other at the end, and check for equality until they meet.”

SQL

1. How do you optimize a SQL query?

This question assesses your knowledge of database performance.

How to Answer

Discuss indexing, query structure, and analyzing execution plans.

Example

“To optimize a SQL query, I would first ensure that the columns used in WHERE clauses are indexed. Additionally, I would analyze the execution plan to identify bottlenecks and consider rewriting the query to reduce complexity, such as avoiding subqueries when possible.”

2. Can you explain the difference between INNER JOIN and LEFT JOIN?

Understanding joins is essential for working with relational databases.

How to Answer

Clarify the differences in how data is retrieved from tables.

Example

“An INNER JOIN returns only the rows that have matching values in both tables, while a LEFT JOIN returns all rows from the left table and the matched rows from the right table. If there’s no match, NULL values are returned for columns from the right table.”

3. Write a SQL query to find the second highest salary from a table.

This question tests your practical SQL skills.

How to Answer

Explain your approach and provide the SQL query.

Example

“I would use a subquery to first find the maximum salary and then select the maximum salary that is less than that. The SQL query would look like this: SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees);”

4. What are window functions in SQL?

This question evaluates your advanced SQL knowledge.

How to Answer

Define window functions and provide an example of their use.

Example

“Window functions perform calculations across a set of table rows that are related to the current row. For example, using ROW_NUMBER() can help assign a unique sequential integer to rows within a partition of a result set.”

5. How would you handle NULL values in SQL?

This question assesses your understanding of data integrity.

How to Answer

Discuss methods for dealing with NULLs in queries.

Example

“I would use the COALESCE() function to replace NULL values with a default value in my queries. For instance, SELECT COALESCE(column_name, 'default_value') FROM table_name; ensures that I handle NULLs gracefully in my results.”

Programming Languages

1. What are the main principles of Object-Oriented Programming (OOP)?

This question tests your foundational knowledge of programming concepts.

How to Answer

Discuss the four main principles of OOP: encapsulation, inheritance, polymorphism, and abstraction.

Example

“The main principles of OOP are encapsulation, which restricts access to certain components; inheritance, which allows a class to inherit properties from another; polymorphism, which enables methods to do different things based on the object; and abstraction, which simplifies complex systems by modeling classes based on essential properties.”

2. Explain the concept of immutability in programming.

This question assesses your understanding of data handling in programming languages.

How to Answer

Define immutability and its implications in programming.

Example

“Immutability means that once an object is created, its state cannot be modified. This is important in functional programming and can lead to safer code, as it prevents unintended side effects. For example, strings in Java are immutable, which means any modification creates a new string rather than altering the original.”

3. How do you manage memory in your applications?

This question evaluates your understanding of memory management.

How to Answer

Discuss techniques like garbage collection and manual memory management.

Example

“I manage memory by utilizing garbage collection in languages like Java, which automatically frees up memory that is no longer in use. In languages like C++, I manually allocate and deallocate memory using new and delete, ensuring to avoid memory leaks by keeping track of allocated resources.”

4. What is the difference between synchronous and asynchronous programming?

This question tests your understanding of programming paradigms.

How to Answer

Explain the concepts and their use cases.

Example

“Synchronous programming executes tasks sequentially, blocking the execution until the current task is completed, while asynchronous programming allows tasks to run concurrently, enabling other operations to continue without waiting. This is particularly useful in web applications where I can handle multiple requests without blocking the user interface.”

5. Describe how you would implement error handling in your code.

This question assesses your approach to writing robust applications.

How to Answer

Discuss strategies for error handling, such as try-catch blocks and logging.

Example

“I implement error handling using try-catch blocks to catch exceptions and handle them gracefully. Additionally, I log errors to a file or monitoring system to track issues and improve the application over time. This ensures that users have a smooth experience even when errors occur.”