Internal Applications Developer

Full-time
· On-site Brooklyn, NY for the first 3-4 months with an opportunity to be hybrid after that. Reports to the HR Director with a dotted line reporting to the Chief Information Officer.

We are seeking a skilled, detail-oriented Internal Applications Developer to help build and maintain the internal software that supports our organization's business, HR, payroll, finance, and administrative operations.

In this role, you will design and develop custom web applications, internal tools, and reliable data integrations. A primary focus will be connecting our internal budget, financial and employee systems with core enterprise platforms, including ADP Payroll and Net Suite Financials.

The ideal candidate has a strong foundation in software development and systems logic, enjoys building intuitive tools for internal users, and cares deeply about data correctness, security, and system reliability. The position works the same schedule as the Business Office staff working 12 months a year and through the summer months.

Key Responsibilities

• Custom Application Development:
  Design, prototype, and build homegrown web applications and internal utilities to streamline HR, payroll, finance, and business office workflows.

• API Integration & Architecture:
  Build, test, and maintain secure, reliable API integrations between our custom Student Information System (SIS), ADP, Net Suite, and other internal systems.

• Data Validation & Reliability:
  Develop automated validation processes to help ensure employee, payroll, and financial data syncs accurately without duplicate entries, missing fields, or data loss.

• Database Management:
  Write efficient queries, manage database schemas, and map data across multiple systems.

• User-Centric Tooling:
  Work closely with HR, finance, and administrative staff to translate business requirements into clean, practical dashboards, forms, reports, and workflows.

• Security & Auditability:
  Help ensure internal applications include appropriate permissions, logging, and audit trails for sensitive HR, payroll, budget, financial, and employee systems.

• Support & Maintenance:
  Troubleshoot bugs, investigate data issues, improve existing tools, and provide technical support to internal users.

Qualifications & Skills

• 2-3 years’ experience working in a business/office environment in an application development role

• Strong experience with C# and the .NET platform (.NET Core / .NET
  8), and modern web application development.

• Experience building web applications and services with Core (MVC, Razor Pages, or Web API).

• Experience working with relational databases, especially Microsoft SQL Server, including writing efficient T-SQL queries and working with stored procedures.

• Experience working with REST APIs, webhooks, JSON data structures, and third-party integrations.

• Working knowledge of front-end web fundamentals (HTML, CSS, and JavaScript) for building clean, usable interfaces.

• Understanding of data integrity, validation, error handling, and reliable system design.

• Ability to collaborate with nontechnical stakeholders, gather requirements, and explain technical concepts clearly.

• Strong attention to detail, especially when working with sensitive or business-critical data.

• B.S. in Computer Science or a related field, or equivalent practical experience in software development.

Preferred Qualifications

• Experience with ADP, Net Suite, payroll systems, ERP systems, HR systems, or school administration software.

• Experience building internal business applications, dashboards, approval workflows, or reporting tools.

• Experience hosting and deploying applications on IIS / Windows Server, and familiarity with Git for version control.

• Familiarity with data-access approaches such as or Entity Framework Core.

• Ex…