Senior Software Engineer — C# (.NET Core) | API Development

Work Schedule

Standard (Mon-Fri)

Environmental Conditions

Office

Job Description

Experience Level: 6–9 Years

Team: Data Governance and Analytics
Organization: Data, AI, and Visualization (DAIV), Global Software R&D

About the team

The Data Governance and Analytics Team is part of Data, AI, and Visualization (DAIV) within our global software R&D organization. We are a diverse, distributed team with colleagues across France and the Netherlands.

We bring digital technology into our products, solutions, and services, enabling data extraction, analysis, and connectivity. We develop software that supports data governance by managing data definitions, improving data quality, and making data more usable and useful. Our work prepares the organization for the age of AI, supports data-driven design, and enables value creation from data.

About the role

We are seeking a highly skilled Senior Software Engineer specializing in C# (.NET Core) and robust API Development. In this role, you will design, build, and scale high-performance backend microservices and secure, enterprise-grade RESTful APIs. You will work closely with cross-functional architecture, product, and platform teams to deliver scalable services that power our core product ecosystem and support seamless system integration.

Key Responsibilities

• Design, development, and lifecycle management of scalable, secure, and well-documented RESTful APIs and microservices using C# and .NET Core.
• Design efficient data access layers, database schemas, and LINQ queries using Entity Framework, ensuring optimal performance, change tracking, and migration management.
• Design, develop, test, and maintain C# software libraries and reusable components supporting data extraction, analysis, connectivity, and governance.
• Translate functional and technical requirements into clear software designs and implementations.
• Develop components that support consistent data definitions, validation, and data quality.
• Identify opportunities to reuse existing software and reduce duplication across products and projects.
• Support the integration of libraries and components into applications and engineering workflows.
• Develop and maintain automated tests to validate functionality and prevent regressions.
• Contribute to build pipelines, test automation, and automated deployment using GitLab or GitHub.
• Apply secure development practices and support DevSecOps activities within the development lifecycle.
• Investigate defects, troubleshoot integration issues, and improve software reliability.
• Maintain technical documentation and clear runbooks covering component interfaces, configuration, integration dependencies, and usage.
• Collaborate with software architects and engineers across the wider R&D organization.
• Establish strong reliability practices (logging/monitoring, retries/backoff, idempotency, concurrency controls, safe cleanup, traceability).
• Mentor engineers through code reviews, best practices, and technical leadership.
• Work effectively within an Agile Scrum / SAFe framework, participating in backlog refinement, sprint planning, technical estimation, PI planning, reviews, retrospectives, and cross-team coordination to support predictable and high-quality delivery.

Required Skills

• Strong Working knowledge of C#, .NET Core and object-oriented software development with API development, Database experience.
• Experience integrating shared libraries or components across multiple applications.
• Experience with both relational and non-relational databases (e.g., MariaDB, MongoDB, PostgreSQL, SQL Server).
• Proven experience designing, building, versioning, and securing RESTful APIs at scale.
• Ability to develop and maintain modular, reusable software components.
• Understanding of software testing, debugging, and version-control practices.
• Experience working in an agile DevOps environment.
• Experience using GitLab or GitHub for source control and collaborative development.
• Familiarity with build pipelines, automated testing, and automated deployment.
• Understanding of containerization concepts, with familiarity with technologies such as Docker, K8s, Helm, etc
• Ability to collaborate effectively with colleagues in a distributed international team.
• Working knowledge of Agile delivery frameworks, including Scrum and SAFe, with experience operating effectively in sprint-based and cross-team planning environments.
• Strong communication and stakeholder management skills, with the ability to work effectively across global, cross-functional teams.
• Experience operating in structured product-development environments with strong quality, compliance, and delivery expectations

Preferred Qualifications

• Bachelor’s or master’s degree, preferably in a technical or scientific discipline.
• 6+ years of software engineering experience with a strong focus on C# and .NET Core and object-oriented software development with API development, Database experience.

Welcome

Thank you for your interest as you consider starting a new career journey with us. As the world leader in serving science, our colleagues develop critical solutions through innovation—and build rewarding careers. Discover their extraordinary stories and connection to our Mission to enable our customers to make the world healthier, cleaner and safer. Their work is a story of purpose. What story will you tell?

About Us

Thermo Fisher Scientific Inc. is the world leader in serving science, with annual revenue of more than $40 billion. Our Mission is to enable our customers to make the world healthier, cleaner and safer. Whether our customers are accelerating life sciences research, solving complex analytical challenges, increasing productivity in their laboratories, improving patient health through diagnostics or the development and manufacture of life-changing therapies, we are here to support them. Our global team delivers an unrivaled combination of innovative technologies, purchasing convenience and pharmaceutical services through our industry-leading brands, including Thermo Scientific, Applied Biosystems, Invitrogen, Fisher Scientific, Unity Lab Services, Patheon and PPD.

Accessibility/Disability Access

We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment. Please contact us to request accommodation.

EEO

Thermo Fisher Scientific is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, creed, religion, color, national or ethnic origin, citizenship, sex, sexual orientation, gender identity and expression, genetic information, veteran status, age or disability status.