Preparing for an interview at Milliman requires a dual focus on deep technical execution and strong communication. You must show that you can not only write high-quality code but also explain why your solution is correct and how it fits into the broader business ecosystem.

Role-Related Knowledge – You must demonstrate a commanding grasp of Object-Oriented Programming principles and database design. Depending on the team you interview with, deep familiarity with either C# / .NET or Java is highly valued. You should be prepared to discuss language-specific memory management, concurrency models, and framework best practices.

Problem-Solving & Testability – Milliman engineers care deeply about edge cases and validation. When writing code—whether on a whiteboard, in an online text editor, or during a take-home test—always write unit tests. You must show that you proactively think about how to break your own code and how to validate its correctness under extreme inputs.

Communication & Simplification – Because you will work alongside actuaries, quantitative analysts, and business consultants, your ability to translate highly technical engineering concepts into plain English is a critical hiring signal. Practice explaining complex algorithms, system designs, or architectural trade-offs simply and concisely.

Ownership & Professional History – Expect to be grilled on the details of your resume. You should be prepared to explain the business impact, technical details, and team dynamics of every past role listed. Be ready to own both your successes and the lessons learned from project failures.

The interview process at Milliman is thorough and designed to evaluate both your immediate technical capabilities and your long-term alignment with the team's engineering standards. Because Milliman operates as a decentralized network of practices, the exact sequence of steps can vary depending on the specific office and team (e.g., Seattle, Chicago Trading, or Brookfield). However, most candidates experience a structured progression that tests core skills before moving to intensive onsite evaluations.

The journey typically begins with an initial recruiter screen to align on your background, technical stack preferences, and compensation expectations. This is followed by a technical screening phase, which may consist of a technical video call with a senior developer, an online coding assessment, or a take-home programming test (such as building a console application to process data).

If you pass the screening stage, you will be invited to a comprehensive final round. Historically, this has been an intensive in-person or virtual loop lasting between three and four hours. During this loop, you will meet with multiple small panels or pairs of engineers, engineering managers, and architects. These sessions cover deep-dive technical definitions, live coding or system design, project retrospectives, and behavioral discussions.

This visual timeline outlines the typical progression from your initial application to the final hiring decision. You should interpret this as a guide to pacing your preparation: focus on core CS definitions and basic coding for the initial screens, and save your deep-dive system architecture and behavioral storytelling practice for the final loop. Note that some offices may bypass the take-home test in favor of live-paired programming sessions during the final round.

Object-Oriented Design & Architecture

At Milliman, software must be maintainable, extensible, and robust enough to handle complex calculations over decades of product lifecycles. Interviewers will evaluate your ability to design systems using clean, object-oriented paradigms.

Be ready to go over:

• Design Patterns – When and how to apply patterns like Factory, Strategy, Singleton, and Observer to solve real-world design problems.
• SOLID Principles – A deep, practical understanding of how to write modular code that is easy to test and refactor.
• Domain Modeling – How to translate complex business rules (e.g., insurance policy rules or trading strategies) into clean class hierarchies.

Advanced concepts (less common):

• Domain-Driven Design (DDD) principles
• CQRS (Command Query Responsibility Segregation) patterns
• Multi-tenant software architecture patterns

Example scenarios:

• "Design a parking lot system, explaining how you would handle different vehicle types, pricing strategies, and real-time spot allocation."
• "How would you refactor a legacy, 2000-line monolithic calculation method into a clean, testable suite of strategy classes?"

Practical Coding & Testability

Milliman values engineers who write production-grade code that is self-documenting and thoroughly tested. You will likely be asked to write code in a live environment or complete a remote programming challenge.

Be ready to go over:

• Unit Testing Frameworks – Writing comprehensive tests using tools like JUnit, NUnit, or xUnit.
• Test-Driven Development (TDD) – The ability to write tests before or alongside your implementation to prove correctness.
• Edge Case Identification – Handling null pointers, boundary limits, empty collections, and data type overflows.

Advanced concepts (less common):

• Mocking frameworks and dependency injection containers
• Performance profiling and memory footprint optimization
• Code coverage metrics and their practical limitations

Example scenarios:

• "Create a console application that processes a CSV file containing financial transactions, applies validation rules, and outputs a summary while writing the unit tests to verify your logic."
• "Write an algorithm to reverse a linked list, and then write the exact test cases you would use to verify its correctness in a production pipeline."

Data & SQL Proficiency

Nearly every application at Milliman interacts with massive databases containing healthcare records, pension data, or market feeds. Your ability to write high-performing queries and design clean schemas is critical.

Be ready to go over:

• Query Optimization – Analyzing execution plans, identifying bottlenecks, and utilizing indexes correctly.
• Relational Schema Design – Designing normalized tables with appropriate primary and foreign keys.
• Aggregations & Analytics – Using complex joins, subqueries, and window functions to extract business insights.

Advanced concepts (less common):

• Partitioning strategies for ultra-large databases
• NoSQL vs. Relational database trade-offs in financial systems
• Database transaction isolation levels and concurrency control

Example scenarios:

• "Given a schema with millions of policy records, write an optimized query to calculate the average premium per region, ensuring you avoid table scans."
• "How would you design a database schema to support a historical audit trail of changes made to user benefit selections?"

Behavioral & Topgrading

Some Milliman offices utilize a structured behavioral interview methodology known as Topgrading. This involves a highly detailed, chronological walkthrough of your entire career history.

Be ready to go over:

• Chronological Career Walkthrough – For every major role on your resume, expect to discuss your specific responsibilities, your proudest achievements, your biggest mistakes, and what your managers would say are your strengths and development areas.
• Communication & Collaboration – Demonstrating how you resolve conflicts with peers, align with product managers, and explain technical risks to leadership.
• Adaptability – Showing how you handle shifting priorities, legacy codebases, and ambiguous requirements.

Advanced concepts (less common):

• Managing up and influencing technical direction without formal authority
• Mentoring junior engineers and driving engineering culture improvements

Example scenarios:

• "Tell me about a time when you realized a project was going to miss its deadline. How did you communicate this to stakeholders, and what mitigation steps did you take?"
• "Walk me through your previous role: What were you hired to do, what was your biggest challenge, and why did you decide to transition to your next opportunity?"

As a Software Engineer at Milliman, your day-to-day responsibilities will vary depending on your practice group, but they generally encompass the following core areas:

• Designing and Developing Core Software – You will write clean, maintainable, and highly performant code to build financial modeling systems, healthcare analytics platforms, or risk assessment tools. You will ensure your systems are scalable, secure, and capable of processing large-scale computations.
• Collaborating with Domain Experts – You will work closely with actuaries, financial consultants, and quantitative analysts. You will translate complex mathematical formulas, regulatory requirements, and business logic into high-performing software algorithms.
• Ensuring Code Quality and Test Coverage – You will take ownership of the quality of your deliverables by writing robust unit, integration, and regression tests. You will participate in rigorous code reviews, ensuring that the team's architectural standards are upheld.
• Optimizing Data Pipelines and Databases – You will design, implement, and optimize database schemas, queries, and data ingestion pipelines to ensure fast, reliable access to critical financial and health data.
• Maintaining and Modernizing Legacy Systems – Many of Milliman's core calculation engines are highly sophisticated and have been refined over years. You will be responsible for maintaining these critical systems while systematically refactoring and modernizing them for cloud environments.

To be competitive for a Software Engineer position at Milliman, you should possess a strong foundation in computer science and a practical, quality-first approach to software development.

Technical Skills

• Must-have skills:

  • Proficiency in at least one major object-oriented programming language, such as Java, C#, or C++.
  • Strong relational database skills, including advanced SQL querying, schema design, and query optimization.
  • Demonstrated experience with unit testing frameworks (e.g., JUnit, NUnit) and writing highly testable code.
  • Solid understanding of core data structures, algorithms, and software design patterns.

• Nice-to-have skills:

  • Experience with cloud platforms, particularly Microsoft Azure or AWS.
  • Familiarity with modern front-end frameworks like React or Angular for full-stack roles.
  • Knowledge of data processing tools and frameworks (e.g., Python, Spark, or pandas).
  • Background or interest in financial services, actuarial science, quantitative finance, or healthcare analytics.

Experience & Soft Skills

• Experience level: Typically requires a Bachelor's degree in Computer Science, Software Engineering, Mathematics, or a related quantitative field. Prior professional experience as a software engineer is highly valued, particularly in environments that demand high numerical precision and rigorous data processing.
• Soft skills:
  • Exceptional communication skills, with the ability to explain complex technical designs to non-technical business partners.
  • A strong sense of ownership, attention to detail, and a disciplined approach to code quality and documentation.
  • Collaborative mindset, comfortable working in small, autonomous teams where developers wear multiple hats.