Capital One Software Engineer Interview Questions + Guide in 2025

Capital One is a large fintech company that serves both as a bank and as a credit card issuer. As of 2024, it was the third-largest issuer of Visa and Mastercard. It has been recognized as one of the best companies to work for by Fortune, ranking 15th in 2023 and 2024. Employee satisfaction is high, with 88% of associates saying it is a great place to work.

Securing a software engineer position at Capital One is a coveted opportunity. The company is known for cutting-edge banking technology, innovation, and a customer-first approach. As a diversified bank, it offers a variety of financial products and services to consumers, small businesses, and commercial clients. Software engineers are the driving force behind these innovative digital solutions, collaborating with other teams to solve complex problems and improve banking for millions of customers.

Capital One fosters a culture of continuous learning and innovation by providing engineers with specialized training programs, advanced tools, and learning opportunities to build new skills. This allows software engineers to grow while working on industry-leading innovations.

If you’re planning to apply for a software engineer role at Capital One, this guide will walk you through the interview process, common interview questions, and useful resources to help you succeed.

Software engineers at Capital One work on a wide range of projects, from customer-facing web and mobile applications to back-end Java-based systems. These projects often involve technologies like Java, JavaScript, Python, REST APIs, open-source RDBMS and NoSQL databases, and a variety of AWS tools and services. Within Agile teams, they collaborate to design, develop, test, and support technical solutions. Capital One engineers also maintain cloud infrastructure, build automation and monitoring solutions, and stay on top of tech trends through continuous learning and experimentation.

This is all supported by Capital One’s significant investment in its technology teams, as seen in the growth of its software engineering workforce from 10,000 to 14,000 between 2021 and 2023. The company is also adopting a hybrid work model for the majority of its associates, balancing collaboration and flexibility, with fully remote options available with senior executive approval.

Beyond core development, Capital One offers specialized opportunities within teams like:

Capital One Labs – Engineers in Labs work on emerging technologies like AI, blockchain, and new banking experiences to create next-generation financial products and services.

Digital Innovation – These teams focus on modernizing banking through new digital solutions, enhancing mobile and online banking experiences.

Capital One & AWS Partnership

In 2020, Capital One fully migrated to the cloud, making AWS its primary cloud provider. This shift allowed the company to move faster, scale efficiently, and focus on building applications that provide real value to customers—without the overhead of managing physical data centers.

Usha, a Senior Software Engineer at Capital One, highlighted the benefits of this transition:

“Capital One is one of the first banks that decided to move to the Amazon Web Services (AWS) Cloud, and it’s paying off right now since there’s no need to invest heavily in managing data centers and servers. With AWS, we can quickly spin up a database or any resources in minutes and scale it based on need.”

Capital One’s shift to AWS and serverless architecture reflects its commitment to innovation and efficiency. By embracing cutting-edge technology, the company continues to enhance customer experiences and empower engineers to build the future of banking.

Qualifications

Capital One seeks software engineers with specific requirements that vary by position and seniority. Although, there are standard qualifications across all levels:

• Preferred: a bachelor’s degree in computer science or a related field—however, Capital One also offers programs like the Capital One Developer Academy (CODA) for graduates from non-traditional CS backgrounds.
• Intermediate to advanced coding experience and knowledge of programming languages like Java, JavaScript, Python, SQL, or Go.
• For entry-level roles: at least 2 years of software engineering experience, while senior roles may need up to 4 years—internship experience usually does not count toward this requirement.
• Experience with cloud-native technologies, particularly Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform.
• Familiarity with Agile development practices and preferably experience in open-source frameworks.

Capital One offers competitive salaries for software engineers, with pay varying by experience level and location. Compensation can range from $124,000–$153,000 per year, including base pay and bonuses.

Capital One Developer Academy

The Capital One Developer Academy (CODA) is a six-month program that trains non-computer science majors for software engineering roles at Capital One. It provides comprehensive training in coding, full stack web application development, and specialized topics, along with mentorship and access to learning resources. Upon completion of CODA, participants transition into the Technology Development Program to continue building their skills and working on impactful projects.

CODA has been successful in bringing in new engineering talent, with Capital One hiring around 200 graduates each year. The program serves as both a pathway to tech careers and strengthens Capital One’s recruitment and retention strategy.

Capital One’s interview process for software engineering roles is structured to assess both technical proficiency and cultural fit. Some stages may be conducted virtually, and video is required for all virtual screenings and on-site interviews. Here’s an overview of what to expect:

1. Recruiter Call

   This is an initial phone call to discuss the role, your background, and career goals. It typically lasts about 30 minutes and includes details about the interview process. You’ll also have the opportunity to ask questions about the role.

2. Online Assessment

   For software engineers, the assessment includes coding tasks via CodeSignal, featuring algorithm and data structure questions ranging from easy to hard. You typically have around 1.5 hours to complete the test.

3. Power Day (On-site Interview)

   Capital One’s “Power Day” includes four sessions, each lasting an hour:

   Coding

   This session will assess your technical skills through coding. It focuses on algorithm and data structure questions of easy to medium-level difficulty.

   System Design

   Here, you will present a system design solution. As much as possible, clearly communicate your thought process, decision-making, and trade-offs of your design. To stay organized, consider using a system design framework.

   Behavioral

   This is pretty much similar to other behavioral interviews, but to stand out, demonstrate competencies like problem-solving, influence, and a focus on results.

   Case Study

   The case study interview assesses your strategic and analytical skills by presenting a practical business problem similar to the work performed daily in the role. When answering hypothetical questions, justify your decisions with a cost-effective approach.

4. Team Matching

   After completing your on-site interviews, each interviewer submits a hire or no-hire recommendation. If only one team is interested, you’ll receive a direct offer. However, if multiple teams express interest, you’ll have brief meetings with each hiring manager to learn about their projects and team dynamics. This process allows you to choose the team that aligns best with your interests and career goals before receiving an official offer.

The interview questions for the software engineer role at Capital One typically cover the following topics:

• Data structures and algorithms
• System design
• Case studies
• Behavioral questions

Data Structures and Algorithms

Capital One includes data structures and algorithms (DSA) in its software engineering interviews to assess problem-solving skills, coding efficiency, and technical depth.

1. Implement a function to reverse a linked list.

   Reversing a linked list requires adjusting pointers so each node points to the previous one. Decide between an iterative or recursive approach while handling edge cases like empty or single-node lists.

2. Solve a problem using a hashmap to optimize time complexity.

   Using a hashmap can significantly reduce time complexity in problems that involve frequent lookups, counting, or detecting duplicates.

3. Given a dataset, draw a rough graph to show how it changes over time.

   When visualizing data, focus on what trends or patterns need to be highlighted. Consider whether the data changes over time or falls into categories, and choose the appropriate graph to use for representation.

4. Given two sorted lists, write a function to merge them into one sorted list.

   Your goal here is to merge two sorted linked lists into one sorted list while keeping the order intact. Think about how you can compare elements from both lists and build the merged list efficiently. Consider the most efficient way to go through both lists without unnecessary operations.

5. Write a function, search_list, that returns a Boolean indicating if the target value is in the linked_list or not.

   You are given the head of a linked list, represented as a dictionary with two keys:

    value: the node’s data.
    next: the next node or None if it's the last node.
   

   If the list is empty, the head will be None. Your task is to check if a given target value exists in the list.

System Design

The focus on system design questions is to assess your ability to design scalable, fault-tolerant, and efficient systems.

1. Build a schema for a relational database with elements X, Y, and Z.

   Identify the relationships between X, Y, and Z and define tables with primary and foreign keys. Ensure normalization to avoid redundancy and improve efficiency.

2. How would you design a system that provides real-time search suggestions as a user types a query?

   Speed and accuracy are key to designing a system that provides real-time search suggestions. The system needs to quickly process user input, retrieve relevant suggestions, and scale efficiently as traffic grows.

3. What is the difference between an API gateway and a load balancer?

   API gateways and load balancers are often confused, but they serve different purposes. An API gateway is like the front door to a system, while a load balancer is more about distributing network traffic evenly across multiple servers to ensure no single machine gets overwhelmed. While they’re different, they often work together.

4. Design a file system that supports basic operations like read, write, and delete.

   Support read, write, and delete operations using a hierarchical structure (directories and files). Consider hashmaps for metadata storage and linked lists for efficient data access.

5. Design a banking system that can process deposits, withdrawals, and transactions.

   Think about how a banking system must process deposits, withdrawals, and transactions while ensuring security and efficiency. Choose an approach that balances security, scalability, and performance while meeting financial regulations.

Case Study

The case studies are designed to mimic real-world problems faced at Capital One. You will be presented with a hypothetical business situation and asked to develop a solution.

1. Explain the Agile process and how you’ve applied it in past projects.

   Agile focuses on iterative development, collaboration, and flexibility. When answering, focus on how you’ve worked in cross-functional teams, managed changing requirements, and used continuous feedback to improve software delivery.

2. How would you determine the cost of a software upgrade based on different update cycles?

   Think about the resources, time, and risks involved in each update cycle. Weigh the trade-offs between longer cycles (bigger updates but more downtime and complexity) and shorter cycles (smaller, frequent updates with lower risk but higher maintenance). Choose the approach that balances cost, efficiency, and system stability.

3. A new mobile app feature allows users to lock/unlock their credit cards, but adoption is low. How would you analyze and improve user engagement?

   For the low adoption of the lock/unlock credit card feature, start by identifying the root cause. Look at user behavior analytics, feedback, and potential friction points in the user experience. Consider A/B testing, targeted notifications, or simplifying the feature’s discovery and usability to improve engagement.

4. You need to migrate a legacy banking system to the cloud, but teams have conflicting priorities. How would you align stakeholders and drive the project forward?

   Understand each team’s concerns, highlight the long-term benefits of cloud migration (like cost savings and scalability), and find a compromise that addresses immediate business needs while keeping the migration on track. Clear communication and phased implementation can help ease resistance.

5. A system outage causes failed transactions. How would you diagnose and resolve the issue?

   Start by diagnosing the issue, like looking for reports of errors or other factors. Then, contain the impact by applying quick fixes or rollbacks. Finally, you can refine monitoring systems to detect issues early or look for other approaches that could prevent future outages.

Behavioral Questions

These questions will help in evaluating your soft skills, teamwork, and cultural fit. The STAR method is a common tip, but using it will help you structure your answers effectively.

1. What makes you a good fit for our company?

   Think about the qualities that make you unique among other candidates. Consider what you could offer not just in the role but to the company as well. On top of these, align your answers to the job description and how the role requirements match your qualities, skills, achievements, and experience.

2. Describe a time you and a coworker had a disagreement and how you handled it. Talk about how you handled the situation by acknowledging your coworker’s perspective while also sharing your sentiment regarding the situation. Highlight how you maintained professionalism and found common ground.

3. How do you handle conflict in the workplace?

   When answering this question, focus on how you resolve the situation. Don’t forget to mention what you learned from that incident or how it shaped your character.

4. What are your strengths and weaknesses? You can choose the strengths that align with the role and show how they contribute to your success. In terms of your weaknesses, be honest, acknowledge an area for improvement, and explain the steps you’re taking to grow in that area.

5. Describe a time you went above and beyond for work.

   Think of a time when you took extra initiative to solve a problem or improve a project. Describe the situation, the extra effort you put in, and the impact it had.

Aside from this article, Interview Query provides additional resources that can help you prepare for your Capital One software engineer interview. Below is a breakdown of what we offer:

• Mock Interviews: Practice makes perfect! Prepare for your interviews with thousands of Interview Query members.
• Interview Questions: Explore a wider range of interview questions across different topics, positions, difficulty levels, and companies.
• Get Coaching: Our personalized coaching ensures you’re prepared, confident, and ready to land your dream job.

Hope these resources help you in your preparation—best of luck, and may the odds be in your favor!