Software Engineer (.NET, Cloud, Data Systems) - Intermediate

Seneca Holdings; Rock Island (IL); On-site; USD 98,000 - 117,000; Full time

Job summary

Seneca Holdings seeks an Intermediate Software Developer for Rock Island Arsenal, Rock Island, IL. You will build and maintain full‑stack web applications using C#, .NET, and SQL Server to support Army modernization and mission‑critical systems.

You will develop backend services, APIs, data solutions, and ensure secure coding practices while collaborating with government and contractor teams. Onsite work with some remote flexibility and clearance requirements.

Qualifications

• Minimum of three years of professional experience developing full‑stack web applications.
• Strong proficiency in C#, .NET Framework and .NET Core, and SQL development.
• Strong analytical, communication, and problem‑solving skills.
• Active Secret Security Clearance - ability to obtain interim clearance to start.

Responsibilities

• Design, develop, test, deploy, and maintain full‑stack web applications supporting Army mission requirements.
• Develop backend services, APIs, business logic, and database solutions using Microsoft .NET technologies and SQL Server.
• Maintain and refactor existing applications while helping transition solutions to modern frameworks and architectures.
• Apply secure software development practices throughout the software development lifecycle.
• Develop database schemas, stored procedures, functions, indexes, and version‑controlled database scripts.
• Collaborate with government and contractor teams to implement enhancements and mission‑driven capabilities.
• Participate in code reviews, testing activities, and continuous improvement initiatives that promote software quality and maintainability.
• Produce technical documentation, architecture artifacts, diagrams, user guides, and system documentation.
• Be onsite fill‑time with flexibility to work from home when needed.
• Keep up to date on required trainings and certifications.

Skills

C#

Microsoft .NET Framework

NET Core

SQL development

HTML5

CSS

jQuery

Secure Software Development Practices

Application Modernization

Enterprise Data Management

Tools

SQL Server

Azure cloud environment

Job description

Western Door Federal is part of the Seneca Nation Group (SNG) portfolio of companies. SNG is Seneca Holdings’ federal government contracting business that meets mission‑critical needs of federal civilian, defense, and intelligence community customers. Our portfolio comprises multiple subsidiaries that participate in the Small Business Administration 8(a) program. To learn more about SNG, visitthe website and follow us onLinkedIn.

Our team of talented individuals is what makes us successful. To support our team, we provide a balanced mix of benefits and programs.Your total rewards package includes competitive pay, benefits, and perks, flexible work-life balance, professional development opportunities, and performance and recognition programs. We offer a comprehensive benefits package that includes medical, dental, vision, life, and disability, voluntary benefit programs (critical illness, hospital, and accident), health savings and flexible spending accounts, and retirement 401K plan. One of our fundamental principles is to offer competitive health and welfare benefits to our team members, providing coverage and care for you and your family. Full-time employees working at least 30 hours a week on a regular basis are eligible to participate in our benefits and paid leave programs. We pride ourselves on our collaborative work environment and culture, which embraces our mission of providing financial and non‑financial benefits back to the members of the Seneca Nation.

Supporting Army Readiness and Modernization - Rock Island Arsenal, Illinois

Build Technology That Directly Supports the Warfighter

Western Door Federal is seeking a Software Developer – Intermediate at the Rock Island Arsenal, in Rock Island, IL. Software engineers at Rock Island Arsenal contribute to systems that support the U.S. Army’s chemical, biological, radiological, and nuclear defense mission. Working with the Web System Solutions (WSS) Branch, you will develop and modernize mission‑critical applications that help deliver capabilities to the Warfighter and strengthen Army readiness.

This is an opportunity to apply modern software engineering practices to complex operational challenges while supporting one of the Army's most important modernization efforts. Engineers work across full‑stack web development, database engineering, application modernization, cybersecurity‑focused development, and enterprise information systems.

Purpose

Develop software that directly supports Army modernization, defense acquisition programs, and mission‑critical decision‑making. Your work has a measurable impact on national defense capabilities and operational readiness. Build the software that helps sustain and modernize the U.S. Army.

Technology

Join a team working across modern web development, Microsoft .NET technologies, SQL databases, secure software development practices, application modernization, and enterprise‑scale information systems. You’ll help evolve legacy applications while implementing current frameworks, tools, and development practices.

Lifestyle

Rock Island Arsenal offers the opportunity to perform meaningful technical work while enjoying the quality of life available in the Quad Cities region, including affordable housing, short commutes, recreational opportunities, and a family‑friendly environment. Located in the middle of the mighty Mississippi River.

This role provides opportunities to maintain and leverage a security clearance, enhance technical expertise, expand leadership capabilities, and build a career supporting critical national security missions.

What You Will Do

As a member of the software development team, you will:

• Design, develop, test, deploy, and maintain full‑stack web applications supporting Army mission requirements.
• Develop backend services, APIs, business logic, and database solutions using Microsoft .NET technologies and SQL Server.
• Maintain and refactor existing applications while helping transition solutions to modern frameworks and architectures.
• Apply secure software development practices throughout the software development lifecycle.
• Develop database schemas, stored procedures, functions, indexes, and version‑controlled database scripts.
• Collaborate with government and contractor teams to implement enhancements and mission‑driven capabilities.
• Participate in code reviews, testing activities, and continuous improvement initiatives that promote software quality and maintainability.
• Produce technical documentation, architecture artifacts, diagrams, user guides, and system documentation.
• Be onsite fill‑time with flexibility to work from home when needed.
• Keep up to date on required trainings and certifications.

Technologies You’ll Use

This role is ideal for engineers interested in working with technologies such as:

• C#
• Microsoft .NET Framework and .NET Core
• SQL Server
• HTML5
• CSS
• jQuery
• Secure Software Development Practices
• Application Modernization and Refactoring
• Enterprise Data Management Solutions

Desired Qualifications

Successful candidates will possess:

• Minimum of three years of professional experience developing full‑stack web applications
• Strong proficiency in C#, Microsoft .NET Framework and .NET Core, and SQL development (SQL database scripts)
• Strong analytical, communication, and problem‑solving skills
• Ability to recommend technical solutions that improve performance, quality, schedule, and cost outcomes
• Commitment to software quality, testing, documentation, and continuous improvement
• Active Secret Security Clearance - we will apply for your clearance if you do not have one, but you must have an interim clearance to start work.
• DoD 8570.01‑M IAT Level One (1) (i.e. Security +) and Technical Certification (i.e., Azure cloud environment) – must obtain within 6 months of starting. Company professional support funds (conditional) are available.

Join a Team Where Technology Meets Mission

At Rock Island Arsenal, software engineers work at the intersection of technology, national security, and modernization. If you’re looking for an opportunity to apply your technical skills to meaningful challenges, advance your career in a mission‑focused environment, and contribute to capabilities that support Army readiness, we encourage you to apply.

Salary at Seneca is based on a variety of factors including but not limited to location, experience, skill set, performance, licensure and certification, as well as contract‑specific affordability and organizational requirements. The range of this position in other geographic locations may differ. The projected compensation range for this position is below. The estimate displayed represents the typical salary range for this position and is just one component of our total compensation package for employees.

The projected compensation range for this position is:: $98,000 USD - $117,000 USD

Equal Opportunity Statement

Seneca Holdings provides equal employment opportunities to all employees and applicants without regard to race, color, religion, sex/gender, sexual orientation, national origin, age, disability, marital status, genetic information and/or predisposing genetic characteristics, victim of domestic violence status, veteran status, or other protected class status. This policy applies to all terms and conditions of employment, including, but not limited to, hiring, placement, promotion, termination, layoff, recall, transfer, leave of absence, compensation and training. The Company also prohibits retaliation against any employee who exercises his or her rights under applicable anti‑discrimination laws. Notwithstanding the foregoing, the Company does give hiring preference to Seneca or Native individuals. Veterans with expertise in these areas are highly encouraged to apply.