Senior Software Engineer (.NET​/React

About the job

Sogeti is seeking a Senior Software Engineer to support the re-platforming of a complex, rules-heavy middleware system using .NET v10 latest LTS, React, and Microsoft SQL Server. This is a hands‑on, execution-focused role working closely with a Solution Architect to understand existing system behavior, implement new backend services and frontend experiences, and ensure functional parity with the current platform. The ideal candidate is comfortable working in ambiguous environments, uses AI tools effectively, and takes ownership of correctness and code quality.

• Implement backend services and APIs using .NET v10 latest LTS
• Translate complex business rules and decision logic into clear, testable code
• Participate in refactoring and decomposition of legacy middleware logic
• Ensure correctness, performance, and reliability of rule execution pipelines

• Build React user interfaces from Figma designs with high fidelity
• Translate UX and visual designs into clean, maintainable components
• Integrate frontend applications with API-driven backend services
• Maintain consistent behavior and validation rules across frontend and backend

• Use AI tools to accelerate code generation, refactoring, and analysis
• Assist in extracting and validating rules from legacy behavior using AI support
• Review and validate all AI-generated code and documentation
• Contribute to team best practices for responsible AI use in development

• Work closely with architects and peers to clarify requirements and edge cases
• Participate in code reviews and design discussions
• Write unit and integration tests for complex logic paths
• Help identify behavioral gaps between the existing and new systems

• 6+ years of professional software engineering experience
• Strong hands‑on experience with .NET v10 latest LTS and C#
• Strong experience with React and modern frontend development
• Experience working with Microsoft SQL Server and data-driven systems
• Proven ability to work in large, complex codebases with minimal documentation

• Experience working on rules-heavy or decision-driven systems
• Experience re‑platforming or modernizing legacy applications
• Practical experience using AI tools as part of daily development work
• Experience converting Figma designs into production-ready frontend code

• Complex business rules are implemented accurately and transparently
• Frontend experiences match design intent and integrate cleanly with backend logic
• AI is used to accelerate development while maintaining code ownership and quality
• The new system behaves predictably and aligns with existing platform outcomes

• Bachelor’s or Master’s in HCI, Psychology, Anthropology, Design, or related field.

• Flexible work options
• 401(k) with 150% match up to 6%
• Employee Share Ownership Plan
• Life Insurance
• Adoption, Surrogacy & Cryopreservation Assistance
• Career Planning & Coaching
• $5,250 Tuition Reimbursement & 20,000+ Online Courses
• Employee Resource Groups
• Counseling & Support for Physical, Financial, Emotional & Spiritual Well-being
• Disaster Relief Programs

Capgemini is an Equal Opportunity Employer encouraging diversity in the workplace. All qualified applicants will receive consideration for employment without regard to race, national origin, gender identity/expression, age, religion, disability, sexual orientation, genetics, veteran status, marital status or any other characteristic protected by law.

This is a general description of the Duties, Responsibilities and Qualifications required for this position. Physical, mental, sensory or environmental demands may be referenced in an attempt to communicate the manner in which this position traditionally is performed. Whenever necessary to provide individuals with disabilities an equal employment opportunity, Capgemini will consider reasonable accommodations that might involve varying job requirements and/or changing the way this job is performed, provided that such accommodations do not pose an undue hardship.

Capgemini is committed to providing reasonable accommodation…