At Marsh, a global leader in insurance brokering and risk management, a Software Engineer does not just write code; you build the digital foundation that helps organizations navigate systemic global risks. As part of Marsh McLennan, the technology teams are responsible for designing, developing, and maintaining complex enterprise platforms that process massive amounts of risk data, automate insurance placements, and power client-facing portals. Whether you are working on cloud automation, modernizing legacy systems, or developing advanced predictive analytics tools, your work directly impacts the resilience of businesses worldwide.

The engineering organization at Marsh operates at an incredible scale, requiring robust system architectures that prioritize security, high availability, and performance. You will be tasked with solving intricate data-engineering challenges, building seamless API integrations, and streamlining cloud operations. The engineering culture values both deep technical expertise and a strong collaborative mindset, as developers frequently work alongside risk analysts, product managers, and cloud architects to translate complex financial and risk frameworks into elegant, scalable software solutions.

Joining Marsh as a Software Engineer means stepping into a highly collaborative, global environment where technology is viewed as a primary business driver. The company is actively modernizing its tech stack, transitioning to public cloud environments, and implementing cutting-edge cloud automation and FinOps practices. For an engineer, this presents a unique opportunity to work on highly visible projects that combine modern software engineering with the stability and impact of a Fortune 500 financial services firm.

The following questions are compiled from real interview experiences at Marsh across various global offices. These questions are representative of what you can expect and are grouped by key technical and behavioral categories to help you identify patterns in how Marsh evaluates talent.

Core CS Fundamentals & Databases

These questions evaluate your understanding of foundational computer science concepts, database design, and query optimization, which are critical for maintaining the high-performance systems at Marsh.

• Explain the four pillars of Object-Oriented Programming (OOPs) and provide real-world examples of how you have applied them.
• What is the difference between an inner join, left join, and outer join in SQL? Write a query to find duplicate records in a table.

To succeed in the Marsh interview process, you must approach your preparation with a balanced focus on core engineering principles, practical system design, and behavioral alignment. Marsh values engineers who are not only technically proficient but also possess the communication skills necessary to collaborate across global, cross-functional teams.

Technical Fundamentals & Core CS – You must have a rock-solid grasp of foundational computer science. Do not skip the basics of OOPs, SQL, Operating Systems, and Computer Networks. Interviewers frequently test these core concepts, especially for entry-level and mid-level roles, to ensure you have a strong engineering foundation.

Problem-Solving & Coding – Practice writing clean, readable code. Focus on string manipulation, array operations, and fundamental data structures. You are not expected to solve ultra-complex competitive programming puzzles, but you must be able to explain your thought process and write bug-free code for standard algorithms.

Architectural & System Design – For mid-to-senior roles, you will be evaluated on your ability to design scalable, secure, and resilient systems. Be prepared to discuss cloud migration, microservices architecture, API design, and how to handle data consistency across distributed systems.

Behavioral & Project Deep-Dives – Your resume is a major focal point of the discussions. Be ready to articulate the business impact of your past projects, the technical choices you made, and how you navigated challenges. Practice structuring your behavioral answers using the STAR method (Situation, Task, Action, Result).

The interview process for a Software Engineer at Marsh is designed to evaluate both your technical depth and your cultural fit. While the process is structured, candidates often report that the exact flow can vary slightly depending on the seniority of the role, the specific office location, and whether you applied through campus placement or an experienced-hire pipeline.

Typically, the process spans 3 to 4 rounds and takes anywhere from 2 to 4 weeks to complete, though candidates should be prepared for potential administrative delays during the final onboarding stages. The initial stage usually begins with an online assessment or an automated video screening, followed by deep technical discussions, architectural evaluations (for senior roles), and a final managerial and behavioral round.

The overall philosophy of the Marsh interview process is conversational yet thorough. Interviewers want to understand how you think, how you approach ambiguity, and how you collaborate with others. They appreciate candidates who are confident, structured in their communication, and genuinely interested in solving the complex risk-management problems that the company faces daily.

The timeline above illustrates the standard progression a candidate goes through from the initial application to the final offer. Most candidates will begin with an online assessment focusing on aptitude and core CS concepts before moving on to live technical interviews. Keep in mind that for senior or specialized roles, the system architecture and managerial rounds will carry significantly more weight.

Data Structures, Algorithms & Coding

This evaluation area focuses on your ability to translate logical solutions into clean, efficient, and maintainable code. Marsh interviewers look for structured thinking, clean code syntax, and an awareness of time and space complexity.

Be ready to go over:

• Array and String Manipulation – Basic operations, searching, sorting, and pattern matching.
• Recursion and Backtracking – Solving classic problems like palindromes, fibonacci, or subset generation.
• Basic Data Structures – Practical implementation and usage of Stacks, Queues, Linked Lists, and Hash Maps.
• Advanced concepts (less common) – Dynamic programming, graph traversals (BFS/DFS), and complex tree manipulations.

Example questions or scenarios:

• Write a program to reverse an array in-place without using extra memory.
• Implement an algorithm to find the first non-repeating character in a string.
• Explain how you would implement a custom stack that supports push, pop, and retrieving the minimum element in constant time.

Core CS Fundamentals (OOPs, DBMS, SQL, Networks)

For almost all software engineering roles at Marsh, a significant portion of the technical evaluation is dedicated to core computer science fundamentals. This ensures that candidates can work effectively across different parts of the enterprise technology stack.

Be ready to go over:

• Object-Oriented Programming (OOPs) – Inheritance, polymorphism, encapsulation, abstraction, and design patterns.
• Database Management Systems (DBMS) – SQL queries, indexing, joins, transactions, and ACID properties.
• Operating Systems & Networking – Process synchronization, memory management, TCP/IP stack, and DNS.

Example questions or scenarios:

• Explain the difference between an abstract class and an interface, and when you would use each.
• Write a SQL query using a subquery or a join to find the second-highest salary from an Employee table.
• What happens under the hood when you type a URL into your browser and press enter?

System Architecture & Cloud Engineering

For experienced roles, such as Cloud Automation, FinOps, or Senior Software Engineer, you will face a dedicated round with architects and engineering managers to evaluate your system design capabilities.

Be ready to go over:

• Microservices Design – Service discovery, API gateways, load balancing, and fault tolerance.
• Cloud Administration & Automation – Infrastructure as Code (IaC), CI/CD pipelines, and public cloud services (AWS/Azure).
• FinOps and Cloud Cost Optimization – Monitoring cloud spend, resource allocation, and automation of cloud resources.
• Advanced concepts (less common) – Event-driven architectures, message queues (Kafka/RabbitMQ), and multi-region failover strategies.

Example questions or scenarios:

• Design a scalable API gateway that handles rate limiting and authentication for multiple microservices.
• How would you automate the provisioning and decommissioning of cloud environments to optimize costs?
• Describe how you would migrate a legacy monolithic application to a modern cloud-native architecture.

Behavioral & Managerial Competencies

The final stages of the interview process assess your soft skills, leadership capabilities, and how well you align with the collaborative, professional environment of Marsh McLennan.

Be ready to go over:

• Conflict Resolution – Navigating disagreements within engineering teams or with product stakeholders.
• Project Ownership – Taking responsibility for a deliverable from design to deployment and post-production support.
• Adaptability – Learning new technologies quickly and adapting to changing business requirements.

Example questions or scenarios:

• Tell me about a time you had to deliver a project with incomplete requirements. How did you proceed?
• Describe a situation where you proposed a technical solution that was initially rejected by your team. How did you handle it?