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

Dataminr is a mission-driven AI company that leverages real-time information from over a million public data sources to empower organizations to respond to critical events and emerging risks before they unfold.

As a Software Engineer at Dataminr, you will be part of a dynamic product engineering team focused on building scalable and efficient systems that handle vast amounts of data. Your key responsibilities will include designing and delivering features for a globally distributed platform, ensuring high availability and performance while working with microservices architecture. You should have extensive experience with backend development, particularly in languages such as Java, Scala, and Python. Strong skills in data structures, algorithms, and object-oriented design are essential, as you will also be involved in API design and data modeling.

The ideal candidate will have a collaborative mindset, as partnering with AI researchers and engineers to integrate innovative AI solutions into production is a significant aspect of the role. Dataminr values diversity and social justice, so a commitment to empathy and allyship in the workplace will be crucial.

This guide aims to equip you with the necessary insights and tips to excel in your interview for the Software Engineer position at Dataminr, helping you to align your skills and experiences with the company's mission and values.

In this section, we’ll review the various interview questions that might be asked during a Software Engineer interview at Dataminr. The interview process will likely focus on your technical skills, problem-solving abilities, and your experience with distributed systems and real-time data processing. Be prepared to demonstrate your coding skills, discuss your past projects, and showcase your understanding of software engineering principles.

Technical Skills

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

Understanding data structures is crucial for this role, and being able to articulate the differences will demonstrate your foundational knowledge.

How to Answer

Discuss the definitions of both data structures, their use cases, and how they operate (LIFO for stacks and FIFO for queues).

Example

“A stack is a data structure that follows the Last In First Out principle, meaning the last element added is the first to be removed. It’s commonly used in scenarios like function call management in programming. A queue, on the other hand, follows the First In First Out principle, which is useful in scenarios like task scheduling where the first task added is the first to be processed.”

2. Describe a time you optimized a piece of code. What was the problem, and what was your solution?

This question assesses your problem-solving skills and your ability to improve existing systems.

How to Answer

Provide a specific example, detailing the initial problem, the steps you took to optimize the code, and the results of your changes.

Example

“In a previous project, I noticed that a data processing function was taking too long to execute. I profiled the code and found that a nested loop was causing inefficiencies. I refactored the code to use a hash map for lookups instead, which reduced the time complexity from O(n^2) to O(n), significantly speeding up the process.”

3. How would you handle a situation where you have to work with a legacy codebase?

This question evaluates your adaptability and problem-solving skills in less-than-ideal situations.

How to Answer

Discuss your approach to understanding legacy code, including documentation review, testing, and incremental refactoring.

Example

“I would start by thoroughly reviewing any available documentation and running existing tests to understand the current functionality. Then, I would incrementally refactor the code, ensuring that I maintain the original functionality while improving readability and performance. I would also add new tests to cover any gaps.”

4. Can you explain the concept of microservices and their advantages?

As Dataminr works with distributed systems, understanding microservices is essential.

How to Answer

Define microservices and discuss their benefits, such as scalability, flexibility, and ease of deployment.

Example

“Microservices are an architectural style that structures an application as a collection of loosely coupled services. This approach allows for independent deployment, scaling, and development of each service, which can lead to increased agility and faster time to market. It also enables teams to use different technologies for different services based on their specific needs.”

5. What is your experience with real-time data processing?

This question assesses your familiarity with technologies and methodologies relevant to Dataminr's work.

How to Answer

Discuss any relevant projects or technologies you have worked with, such as Kafka or Kinesis, and your role in those projects.

Example

“I have worked on a project that involved processing streaming data using Apache Kafka. I designed a system that ingested real-time data from various sources, processed it using a series of microservices, and stored the results in a database for further analysis. This experience taught me the importance of handling data efficiently and ensuring low latency in processing.”

Behavioral Questions

1. Describe a challenging project you worked on. What was your role, and how did you overcome the challenges?

This question helps interviewers understand your teamwork and problem-solving skills.

How to Answer

Provide a specific example, focusing on your contributions and the strategies you used to overcome obstacles.

Example

“I worked on a project that required integrating multiple data sources into a single platform. The challenge was ensuring data consistency and handling discrepancies. I took the lead in designing a robust data validation process and collaborated closely with the data engineering team to implement it. This proactive approach helped us meet our deadlines and deliver a reliable product.”

2. How do you prioritize tasks when working on multiple projects?

This question assesses your time management and organizational skills.

How to Answer

Discuss your approach to prioritization, including any tools or methodologies you use.

Example

“I prioritize tasks based on their urgency and impact. I often use a Kanban board to visualize my workload and adjust priorities as needed. I also communicate regularly with my team to ensure alignment on project goals and deadlines, which helps me manage my time effectively.”

3. How do you handle feedback and criticism?

This question evaluates your ability to accept and learn from feedback.

How to Answer

Discuss your perspective on feedback and provide an example of how you’ve used it to improve.

Example

“I view feedback as an opportunity for growth. For instance, after receiving constructive criticism on my code review practices, I took the initiative to attend a workshop on best practices. This not only improved my skills but also enhanced the quality of my contributions to the team.”

4. Can you give an example of how you worked collaboratively in a team?

This question assesses your teamwork and communication skills.

How to Answer

Provide a specific example that highlights your role in a team setting and how you contributed to the team’s success.

Example

“In a recent project, I collaborated with a cross-functional team to develop a new feature. I facilitated regular stand-up meetings to ensure everyone was aligned and encouraged open communication. This collaborative approach helped us identify potential issues early and deliver the feature ahead of schedule.”

5. Why do you want to work at Dataminr?

This question gauges your interest in the company and its mission.

How to Answer

Discuss your alignment with Dataminr’s values and how you see yourself contributing to their mission.

Example

“I am passionate about using technology for social good, and Dataminr’s mission to provide real-time information to help organizations respond to critical events resonates with me. I believe my experience in building scalable systems aligns well with your goals, and I am excited about the opportunity to contribute to such impactful work.”

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

Understand the Interview Process

The interview process at Dataminr typically includes an initial HR call, followed by a technical phone screen, and then a virtual onsite interview. Familiarize yourself with this structure so you can prepare accordingly. During the technical screen, expect to solve coding problems and discuss your approach. The onsite will likely involve multiple rounds, including coding, design, and behavioral questions. Knowing what to expect can help you manage your time and energy effectively.

Prepare for Technical Questions

Given the emphasis on coding and system design, practice common algorithms and data structures, as well as system design principles. Focus on languages relevant to the role, such as Java, Scala, and Python. Be ready to explain your thought process clearly and concisely, as interviewers appreciate candidates who can articulate their reasoning. Utilize platforms like LeetCode or HackerRank to simulate coding interviews and refine your problem-solving skills.

Emphasize Collaboration and Communication

Dataminr values teamwork and collaboration, so be prepared to discuss your experiences working in teams. Highlight instances where you successfully collaborated with others, especially in a technical context. During the interview, demonstrate your ability to communicate effectively, both in explaining your code and in discussing design decisions. This will show that you can work well within their team-oriented culture.

Showcase Your Passion for AI and Real-Time Data

As a mission-driven company focused on using AI for the greater good, express your enthusiasm for the field and how it aligns with your career goals. Be prepared to discuss any relevant projects or experiences that demonstrate your interest in AI and real-time data processing. This will help you connect with the company's mission and values, making you a more appealing candidate.

Be Ready for Behavioral Questions

Behavioral questions are a key part of the interview process. Prepare to discuss your past experiences, challenges you've faced, and how you've handled them. Use the STAR (Situation, Task, Action, Result) method to structure your responses. This will help you provide clear and concise answers that highlight your problem-solving skills and adaptability.

Ask Insightful Questions

At the end of the interview, you will likely have the opportunity to ask questions. Use this time to inquire about the team dynamics, the company's future projects, or how they measure success in the role. Asking thoughtful questions not only shows your interest in the position but also helps you assess if Dataminr is the right fit for you.

Stay Positive and Professional

While some candidates have reported less-than-ideal experiences during interviews, maintaining a positive and professional demeanor is crucial. Regardless of the interviewer's attitude, focus on showcasing your skills and enthusiasm for the role. A positive attitude can leave a lasting impression and may even influence the interviewer's perception of you.

By following these tips and preparing thoroughly, you can enhance your chances of success in the interview process at Dataminr. Good luck!

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

1. Initial HR Screening

The process begins with a phone call from an HR recruiter. This initial screening lasts about 30 minutes and focuses on verifying your resume, discussing your background, and understanding your motivations for applying to Dataminr. The recruiter will also provide insights into the company culture and the specifics of the role, ensuring that you have a clear understanding of what to expect.

2. Technical Phone Interview

Following the HR screening, candidates typically participate in a technical phone interview with an engineer from the team. This interview is conducted via a collaborative coding platform and focuses on assessing your problem-solving abilities and coding skills. You may be asked to solve algorithmic problems or discuss your previous projects in detail. Expect questions that require you to demonstrate your understanding of data structures, algorithms, and system design.

3. Virtual Onsite Interview

The final stage of the interview process is a virtual onsite, which consists of multiple rounds with different team members. This typically includes: - Coding Round: You will be presented with a coding challenge that tests your ability to write efficient and clean code. This may involve solving problems related to algorithms or data structures. - Design Round: In this round, you will be asked to design a system or component, showcasing your understanding of software architecture and design principles. You may need to discuss trade-offs and justify your design choices. - Behavioral Round: This round is conducted by an engineering manager and focuses on assessing your soft skills, teamwork, and alignment with Dataminr's values. Expect questions about your past experiences, how you handle challenges, and your approach to collaboration.

Throughout the interview process, candidates are encouraged to ask questions and engage with the interviewers to demonstrate their interest in the role and the company.

As you prepare for your interview, it's essential to familiarize yourself with the types of questions that may be asked during each stage.

1. Write a SQL query to select the 2nd highest salary in the engineering department.

Write an SQL query to select the second-highest salary in the engineering department. If more than one person shares the highest salary, the query should select the next highest salary.

2. Write a function to merge two sorted lists into one sorted list.

Write a function to merge two sorted lists into one sorted list. Bonus: What’s the time complexity?

3. Write a function missing_number to find the missing number in an array.

You have an array of integers, nums of length n spanning 0 to n with one missing. Write a function missing_number that returns the missing number in the array. Complexity of (O(n)) required.

4. Write a function precision_recall to calculate precision and recall metrics from a 2-D matrix.

Given a 2-D matrix P of predicted values and actual values, write a function precision_recall to calculate precision and recall metrics. Return the ordered pair (precision, recall).

5. Write a function to search for a target value in a rotated sorted array.

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. You are given a target value to search. If the value is in the array, then return its index; otherwise, return -1. Bonus: Your algorithm’s runtime complexity should be in the order of (O(\log n)).

6. How would you evaluate the suitability and performance of a decision tree model for predicting loan repayment?

You are tasked with building a decision tree model to predict if a borrower will repay a personal loan. How would you evaluate whether a decision tree is a correct model for this problem? If you proceed with the decision tree, how would you evaluate its performance before and after deployment?

7. How does random forest generate the forest and why use it over logistic regression?

Explain how a random forest generates its forest of trees. Additionally, discuss why you might choose random forest over other algorithms like logistic regression.

8. When would you use a bagging algorithm versus a boosting algorithm?

Compare two machine learning algorithms. In which scenarios would you use a bagging algorithm versus a boosting algorithm? Provide examples of the tradeoffs between the two.

9. How would you justify using a neural network model and explain its predictions to non-technical stakeholders?

Your manager asks you to build a neural network model to solve a business problem. How would you justify the complexity of this model and explain its predictions to non-technical stakeholders?

10. What metrics would you use to track the accuracy and validity of a spam classifier?

You are tasked with building a spam classifier for emails and have completed a V1 of the model. What metrics would you use to track the accuracy and validity of the model?

11. Would you suspect anything unusual about the A/B test results with 20 variants?

Your manager ran an A/B test with 20 different variants and found one significant result. Would you consider this result suspicious?

12. How would you set up an A/B test to optimize button color and position for higher click-through rates?

A team wants to A/B test changes in a sign-up funnel, such as changing a button from red to blue and/or moving it from the top to the bottom of the page. How would you design this test?

13. What steps would you take if friend requests on Facebook are down 10%?

A product manager at Facebook reports a 10% decrease in friend requests. What actions would you take to investigate and address this issue?

14. Why might job applications be decreasing while job postings remain constant?

You observe that the number of job postings per day has remained stable, but the number of applicants has decreased. What could be causing this trend?

15. Is this a fair coin based on 10 flips resulting in 8 tails and 2 heads?

You flip a coin 10 times, and it comes up tails 8 times and heads twice. Based on this outcome, determine if the coin is fair.

16. How would you write a function to calculate the sample variance of a list of integers?

Write a function that outputs the sample variance given a list of integers. Round the result to 2 decimal places. Example input: test_list = [6, 7, 3, 9, 10, 15]. Example output: get_variance(test_list) -> 13.89.

17. How would you find the median of a sorted list where more than 50% of the list is the same integer in O(1) time and space?

Given a list of sorted integers where more than 50% of the list is the same repeating integer, write a function to return the median value in (O(1)) computational time and space. Example input: li = [1,2,2]. Example output: median(li) -> 2.

18. What are the drawbacks of the given student test score data layouts, and how would you reformat them for better analysis?

Assume you have data on student test scores in the layouts shown in Dataset 1 and Dataset 2. Identify the drawbacks of these layouts, suggest formatting changes to make the data more useful for analysis, and describe common problems seen in “messy” datasets.

A few tips for acing your Dataminr interview include:

1. Clear Communication: Given the technical nature of the interviews, clearly articulate your thought process and solutions. Clear communication is key to making a positive impression.

2. Research the Company: Gain a solid understanding of Dataminr’s products and services, and be prepared to discuss how your skills and experiences align with the company’s mission and values.

3. Prepare for Rejection: While the interview process may go well, be aware that communication post-interview can be generic. Be prepared for standard rejection letters and consider seeking constructive feedback from the recruiter.

What is the average salary for a Software Engineer at Dataminr, Inc.?

What technical skills are required for a Software Engineer role at Dataminr?

To succeed as a Software Engineer at Dataminr, you should have experience in Java, Scala, Python, or other object-oriented programming languages. You should also be skilled in working with microservices, distributed systems, and real-time streaming data. Strong data structures, algorithms, and API design knowledge are also essential.

Is Dataminr a good place for experienced professionals to work?

While Dataminr offers a collaborative and innovative culture with competitive benefits like comprehensive insurance, PTO, and equity options, reviews suggest that it might be more appealing to interns and those seeking their first job rather than seasoned professionals.

What benefits does Dataminr offer to its employees?

Dataminr provides a comprehensive benefits package that includes medical, dental, and vision insurance, generous PTO, flexible sick days, remote work options, paid parental leave, mental health support, and company equity (RSUs). They also offer reimbursements for mental health and wellness apps.

How does Dataminr handle diversity and inclusion?

Dataminr is committed to fostering diversity and inclusion. It actively condemns racism and discrimination and supports a culture of allyship. Dataminr empowers employees through various opportunities, such as employee resource groups (ERGs) and learning and development funds, to ensure everyone can be their best, most authentic selves.

Dataminr offers a supportive work environment filled with opportunities for growth, meaningful projects, and a culture that celebrates diversity and inclusion. Their competitive benefits package is designed to support you both in and out of the workplace, from comprehensive health plans to generous PTO and parental leave.

Seize this opportunity to make a real-world impact by leveraging your skills in a company that values your unique contributions. Check out our main Dataminr, Inc. interview guide for further help as well!

Good luck with your application and the interview process!