Senior Financial Software Developer Jobs in Groton, CT

We are looking for an intermediate Software Developer to join the NextGen R&D team at Harris School Solutions.

This role will help support and modernize a critical K-12 financial management platform used by school districts to manage accounting, payroll, HR, purchasing, fixed assets, and other core business operations.

This is not a greenfield development role. The successful candidate will work with a mature, mission-critical product that includes both legacy and modern technologies, including Visual Basic 6, SQL Server, Excel macros, custom integrations, IIS deployments, and production support processes. The team is also expanding NextGen 2.0, a modern .NET-based web application using technologies such as C#, Blazor, and WiseJ.

This position is important to the long-term health of the product. The team is transferring deep product knowledge, reducing reliance on individual subject matter experts, modernizing legacy functionality, and changing how software is built through AI-assisted and agentic development practices.

We are looking for someone who can grow into strong technical ownership over time: a developer who is curious, pragmatic, comfortable with complexity, and able to work through imperfect systems. The successful candidate is not expected to know the product on day one, but must be able to learn complex systems, ask good questions, document what they learn, and steadily build ownership.

We are also looking for someone who already uses AI tools as part of their development workflow - not just for code completion, but for code analysis, debugging, test generation, documentation, refactoring, and agent-assisted development.

• Maintain, troubleshoot, and improve the NextGen Classic application, including VB6 components, SQL Server databases, Excel macros, custom scripts, and related legacy technologies.

• Contribute to NextGen 2.0, including bug fixes, enhancements, APIs, modernization work, and customer-driven features.

• Use AI-assisted and agentic development tools to accelerate code analysis, development, debugging, testing, documentation, and knowledge capture.

• Learn and document complex business logic, system dependencies, customer-specific behavior, and K-12 school finance domain concepts.

• Help migrate legacy functionality into modern .NET-based services, APIs, and web application components.

• Write and maintain SQL Server queries, stored procedures, scripts, and data troubleshooting tools.

• Support deployments, release activities, hotfixes, QA collaboration, support-team handoff, and production troubleshooting.

• Work with Product Management, Professional Services, Support, QA, and other R&D team members to investigate issues and deliver practical technical solutions.

• Contribute to internal documentation, AI-ready knowledge bases, and knowledge transfer efforts.

The successful candidate will build working knowledge of the NextGen Classic platform and NextGen 2.0 architecture, contribute to bug fixes and modernization work, support deployments and releases, document important product knowledge, and use AI-assisted workflows to improve development, troubleshooting, testing, and knowledge capture.

Over time, the successful candidate will take increasing ownership of assigned modules, customer issues, and technical areas, becoming a reliable contributor across Classic maintenance, NextGen 2.0 development, production support, and modernization initiatives.

• Bachelor's degree in Computer Science, Software Engineering, Information Systems, or a related field - or equivalent practical experience.

• Typically 3-7 years of professional software development experience, or equivalent demonstrated experience.

• Strong software development fundamentals, with experience in C#, .NET, Java, TypeScript, or another enterprise application development stack.

• Ability to read, debug, modify, and validate code in a complex existing application.

• Experience with relational databases, preferably SQL Server, including writing queries, understanding stored procedures, and troubleshooting data issues.

• Experience with Git-based development workflows using Azure DevOps Repos, GitHub, or similar tools.

• Exposure to web application development, APIs, and modern application architecture.

• Practical experience using AI coding assistants or AI-powered development tools as part of regular development work.

• Ability to validate AI-generated code, analysis, or documentation using sound engineering judgment.

• Willingness and ability to work with legacy codebases, including unfamiliar, complex, or poorly documented systems.

• Experience with C#/.NET, Blazor, WiseJ, or similar Microsoft development technologies.

• Experience with Visual Basic 6, VBA, classic ASP, or other legacy Microsoft technologies.

• Experience using AI tools or agents to analyze unfamiliar codebases, generate tests, document systems, refactor code, or troubleshoot defects.

• Experience modernizing legacy systems into modern web, API, or service-based architectures.

• Experience with CI/CD pipelines, Microsoft Azure, IIS, Windows Server, or multi-tenant application environments.

• Interest in accounting, finance, payroll, HR, K-12 education technology, or public-sector ERP systems.

• Technical ownership: Takes responsibility for understanding issues, following through, and improving the system rather than only completing assigned tasks.

• Curiosity: Enjoys digging into complex systems to understand how they really work.

• Learning agility: Able to absorb technical, product, and domain knowledge over time.

• AI-enabled development: Uses AI tools thoughtfully to improve speed, quality, documentation, testing, and knowledge transfer, while validating outputs with sound engineering judgment.

• Pragmatism: Balances ideal technical solutions with customer needs, operational constraints, and maintainability.

• Resilience: Comfortable working in imperfect, evolving environments with legacy systems, competing priorities, and incomplete documentation.

• Clear communication: Able to explain technical issues, risks, and trade-offs clearly to technical and non-technical stakeholders.

• Collaboration: Works effectively with Product, QA, Support, Professional Services, and other developers to solve customer and product problems.

• Domain interest: Willing to learn the K-12 school business domain in order to make better technical decisions.

Salary: $95,000 - $110,000 per year.