Senior Software Engineer .NET & React

Senior Software Engineer —.NET & ReactWe are looking for an accomplished Senior Software Engineer to design, develop, and modernize scalable enterprise applications. The role centers on API-first, cloud-native solutions built with.NET (C#) for backend services and React for frontend experiences, with a strong focus on security, performance, maintainability, and sound engineering practices.You will partner with architects, product owners, and cross-functional teams to deliver reliable software that meets enterprise standards and regulatory obligations.Primary ResponsibilitiesBackend (.NET)Design, build, and support RESTful APIs and backend services with.NET / ASP.NET Core (C#)Use clean architecture practices, including SOLID, DDD, and CQRS where they add valueImplement effective data access with Entity Framework Core or comparable tools, minimizing unnecessary reliance on stored proceduresBuild systems that are secure, resilient, auditable, and observableHelp shape architecture decisions and produce clear technical design documentationFrontend (React)Develop modern, responsive interfaces with React and TypeScriptCreate reusable component libraries that follow UI/UX and accessibility standardsIntegrate APIs securely and efficiently, including authentication, authorization, and error handlingImprove frontend performance and the overall user experienceDevelop unit and integration tests for frontend componentsEngineering & DeliveryApply CI/CD best practices with tools such as GitHub Actions / Azure DevOpsChampion test-driven development and automated testingContribute to code reviews, mentoring, and knowledge sharingWork with DevOps, QA, and platform teams to enable reliable deploymentsSupport production systems and assist with incident resolution when requiredRequired Qualifications:Essential Technical SkillsAt least 4 years of professional software engineering experienceStrong proficiency in C# and.NET / ASP.NET CoreProven experience building micro-frontends (MFEs) with React and TypeScriptStrong knowledge of REST APIs, fundamentals, and API securityExperience with relational databases such as SQL ServerExperience with cloud platforms, preferably Azure, and containerization with Docker preferred.Hands on experience with Agentic AI SDLC with spec-driven development a plusEngineering PracticesStrong command of object-oriented design, clean code, and refactoringHands-on experience with unit testing, integration testing, and mocking frameworksFamiliarity with event-driven and microservices architectures; Kafka or other messaging technologies are a plusExperience working in agile delivery environments such as Scrum or KanbanPreferred QualificationsExperience in financial services or another highly regulated industryKnowledge of performance tuning, high-volume transaction processing, and distributed systemsProfessional CapabilitiesStrong analytical and problem-solving abilitiesClear, structured communicationAbility to collaborate effectively with senior stakeholders and cross-functional teamsA proactive approach with strong ownership and accountabilityTechnical Leadership:The successful candidate will demonstrate strong technology leadership, shaping solution design and improving engineering practices across teams:Advance modern engineering practices, including API-first design, cloud-native patterns, automation, and technical debt reductionGuide and mentor engineers to strengthen capabilities and promote consistent practices across teamsIdentify technology risks, scalability issues, and non-functional gaps early, then drive practical solutionsBalance immediate delivery needs with long-term platform health, maintainability, and operational resilienceAlignment with Northern Trust Principles:Service & Integrity First – Develop software responsibly, with security, accountability, client trust, and data protection at the forefront.Strength in Collaboration – Partner across engineering, architecture, product, operations, and risk to deliver sustainable, well-designed solutions.Expertise & Continuous Improvement – Apply deep technical expertise while continually improving systems through modernization, automation, and proven engineering practices.Ownership & Accountability – Own solutions end to end, from design through production support, with consistent attention to reliability and quality.Risk & Controls Mindset – Build solutions that satisfy regulatory, compliance, and audit requirements through appropriate controls, logging, and documentation.Client-Focused Engineering – Make technology choices that support scalability, resilience, and lasting client outcomes rather than only short-term delivery.Education and Experience:Bachelor's or Master's degree in Computer Science, Engineering, or a related field, or equivalent practical experienceSalary Range:$114,500 - 194,700 USDSalary range is a good faith estimate of base pay. Northern Trust provides a comprehensive benefits package including retirement benefits (401k and pension), health and welfare benefits (medical, dental, vision, spending accounts and disability), paid time off, parental and caregiver leave, life & accident insurance, and other voluntary and well-being benefits. Northern Trust also provides a discretionary bonus program that may include an equity component.Work AuthorizationApplicants must be authorized to work in the U.S. without the need for employment-based visa sponsorship now or in the future. Northern Trust will not sponsor applicants for U.S. work visa status for this opportunity (no sponsorship is available for H-1B, L-1, TN, O-1, E-3, H-1B1, F-1, J-1, OPT, CPT or any other employment-based visa).Working with UsAs a Northern Trust partner, you will be part of a flexible and collaborative work culture, which has a strong history of financial strength and stability. Movement within the organization is encouraged, senior leaders are accessible, and you can take pride in working for a company committed to an inclusive workplace and assisting the communities we serve.Philanthropy is deeply rooted in Northern Trust's history and is an essential element of our culture. Employees around the world give their time and talent to work for the greater good of their communities.Reasonable AccommodationNorthern Trust is committed to working with and providing adjustments to individuals with health conditions and disabilities. If you need a reasonable accommodation for any part of the employment process, please email our HR Service Center at View email address on click.appcast.io, or alternatively you can discuss your individual requirements with the recruiter you are working with.