Senior Software Engineer (C# / .NET)

PassFort; Brussel Hoofdstad; On-site; EUR 65,000 - 95,000; Full time

Job summary

Moody’s is seeking a senior .NET engineer to join the Orbis platform team. You will own production-grade services across .NET Framework and .NET Core, drive performance improvements, and lead complex issue resolution across large-scale financial data systems.

You’ll design robust architectures, implement AI-enabled workflows, and mentor engineers to uphold high standards. You’ll collaborate with product, design, and data teams to deliver scalable, secure solutions that power Moody’s analytics

Qualifications

• 5+ years delivering production-grade software in full-stack environments.
• Strong command of C# development with ASP.NET MVC, Web API and ASP.NET Core.
• Experience designing software architectures using SOLID, layered and clean architecture principles.

Responsibilities

• Own technical health of .NET Framework 4.8 and .NET 10 apps, ensuring stability, security, and performance.
• Lead analysis/resolution of complex production issues and recurring problems by identifying root causes.
• Drive optimization across app performance, DB queries, indexing, and technical debt reduction.
• Define technical approaches for new features aligned with architectural standards.
• Recommend modernization opportunities, incl. targeted adoption of .NET 10 where suitable.
• Own the full software development lifecycle from design to deployment and monitoring.
• Collaborate with product, design, and data teams to deliver impactful solutions.
• Mentor engineers and promote performance, security, reliability and engineering excellence.

Skills

C# / .NET

ASP.NET MVC

Web API design

Software architecture

SQL Server / EF / ORM

Performance tuning

Distributed systems

AI concepts

Mentoring

Testing strategies

Education

Strong technical foundation

Tools

Entity Framework Core

Dapper / ADO.NET

SQL Server

Job description

At Moody's, we unite the brightest minds to turn today’s risks into tomorrow’s opportunities. We do this by striving to create an inclusive environment where everyone feels welcome to be who they are— with the freedom to exchange ideas, think innovatively, and listen to each other and customers in meaningful ways. Moody’s is transforming how the world sees risk. As a global leader in ratings and integrated risk assessment, we’re advancing AI to move from insight to action—enabling intelligence that not only understands complexity but responds to it. We decode risk to unlock opportunity, helping our clients navigate uncertainty with clarity, speed, and confidence.

Skills And Competencies

• Proven experience delivering production-grade software with end-to-end ownership in a full-stack environment with 5+ years of professional experience
• Expert-level C# development skills with strong command of ASP.NET MVC, Web API (.NET Framework 4.8), and ASP.NET Core (.NET 10)
• Proven ability to design software architecture using layered and clean architecture principles, SOLID principles, design patterns, and API design best practices
• Strong database expertise including SQL Server schema design, query and index optimization, stored procedures, Entity Framework 6, Entity Framework Core, and Dapper or ADO.NET
• Experience with application performance analysis and optimization, including profiling, query tuning, and diagnosing production bottlenecks at scale
• Ability to evaluate architectural and technical trade-offs across scalability, reliability, maintainability, cost, and modernization initiatives
• Experience with asynchronous processing, distributed systems, unit and integration testing strategies, and mentoring engineers through code reviews
• Demonstrated proficiency in artificial intelligence concepts, with hands-on experience using AI tools to streamline workflows and enhance operational efficiency. Proven ability to implement AI-powered solutions to solve business challenges. Demonstrates a growing awareness of AI risk management and a commitment to responsible and ethical AI use

Education

• Strong technical foundation built through formal education, self-directed learning, or hands-on professional experience

Responsibilities

Support and evolve mission-critical applications powering Orbis while driving performance, reliability, security, and modernization initiatives across large-scale financial data platforms.

• Own the technical health of existing .NET Framework 4.8 and .NET 10 applications, ensuring stability, maintainability, security, and performance
• Lead the analysis and resolution of complex production issues and recurring problems by identifying and addressing root causes
• Design and drive optimization initiatives across application performance, database queries, indexing strategies, and technical debt reduction
• Define technical approaches for new features and enhancements, ensuring alignment with existing architectural standards and long-term objectives
• Assess current application architectures and recommend pragmatic modernization opportunities, including targeted adoption of .NET 10 where appropriate
• Own the full software development lifecycle from solution design and implementation through deployment and production monitoring
• Collaborate closely with product, design, and data teams to deliver impactful solutions that support business goals and client needs
• Champion performance, security, reliability, and engineering excellence standards for systems handling sensitive financial data while mentoring engineers and sharing technical knowledge

About The Team

You’ll join the Digital Content & Innovation group within Moody's Analytics, the engineering organization behind moodys.com and the platforms supporting critical financial decision-making for global banks, institutional investors, and corporations. The team responsible for Orbis manages one of the world's largest company information resources, providing data on more than 654 million companies and entities to thousands of clients worldwide. Our engineering teams operate with clear ownership, trunk-based development, code-driven continuous integration and deployment, and modern cloud-based practices. By joining the team, you will work on meaningful technical challenges at scale while helping shape the future of a market-leading financial intelligence platform through high-quality engineering, AI-augmented workflows, and responsible innovation.

Moody’s is an equal opportunity employer.

All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, protected veteran status, sexual orientation, gender expression, gender identity or any other characteristic protected by law.

Candidates for Moody's Corporation may be asked to disclose securities holdings pursuant to Moody’s Policy for Securities Trading and the requirements of the position. Employment is contingent upon compliance with the Policy, including remediation of positions in those holdings as necessary.