Software Development Software Engineer Jobs in Fairfax, VA

US Citizenship is required.

An active TS/SCI is required.

An adjudicated CI Polygraph is required prior to start.

A customer-approved security certification is required: Security+, SSCP, CISSP, or CASP.

Software Engineer

Work Location: Herndon, VA

DPG Solutions is looking for a mid- to senior-level Software Engineer to support a classified customer environment in Herndon, Virginia. This is a hands-on development position for an experienced engineer who can design, develop, integrate, test, troubleshoot, and maintain software supporting mission-critical systems.

The ideal candidate brings a strong foundation in object-oriented software development using C#, Java, C++, or a combination of these languages. You should be comfortable working throughout the software development lifecycle, collaborating with technical and mission stakeholders, and taking ownership of software from initial requirements through integration and operational support.

Experience with SQL, React, and Agile development methodologies is strongly preferred. This position also offers meaningful visibility with the customer and an opportunity to help DPG continue expanding its presence in Virginia.

Responsibilities

• Design, develop, test, integrate, deploy, and maintain software supporting classified mission systems.
• Develop object-oriented software using C#, Java, C++, or related technologies.
• Translate technical and mission requirements into reliable and maintainable software solutions.
• Participate in software architecture, design discussions, technical planning, and implementation decisions.
• Troubleshoot software defects, integration issues, performance problems, and operational failures.
• Develop and maintain unit tests, integration tests, and other automated software validation capabilities.
• Conduct code reviews and contribute to software quality, consistency, security, and maintainability.
• Support database integration, data access, queries, and related development activities using SQL.
• Develop or support user-facing applications and interfaces using React when applicable.
• Collaborate with software developers, systems engineers, cybersecurity personnel, infrastructure teams, testers, and mission stakeholders.
• Participate in Agile development activities, including sprint planning, backlog refinement, daily standups, demonstrations, and retrospectives.
• Maintain software documentation, technical designs, interface definitions, deployment instructions, and configuration records.
• Support software integration, release management, deployment, and operational troubleshooting.
• Follow secure software development practices appropriate for classified and mission-critical environments.
• Provide technical guidance and support to junior engineers when appropriate.

Required Qualifications

• 5 or more years of professional software development or software engineering experience.
• Strong experience with at least one object-oriented programming language, including C#, Java, or C++.
• Strong understanding of object-oriented design principles, data structures, algorithms, and software development fundamentals.
• Experience designing, developing, testing, debugging, and maintaining production software.
• Experience translating requirements into technical designs and working software.
• Experience troubleshooting complex software and integration issues.
• Experience with source control, configuration management, code review, and collaborative software development practices.
• Ability to work independently while contributing effectively within a multidisciplinary engineering team.
• Strong analytical, documentation, communication, and problem-solving skills.
• A customer-approved security certification, including Security+, SSCP, CISSP, or CASP.
• Active TS/SCI with an adjudicated CI Polygraph prior to start.
• US Citizenship.

Desired Qualifications

• Experience with more than one of the following languages: C#, Java, or C++.
• Experience developing database-driven applications using SQL.
• Experience developing modern web applications or user interfaces using React.
• Experience working in Agile development environments using Scrum, Kanban, or similar methodologies.
• Experience with automated testing, continuous integration, continuous delivery, or software deployment pipelines.
• Experience supporting enterprise, distributed, or mission-critical software systems.
• Experience integrating software with databases, external services, system interfaces, or existing applications.
• Experience with software architecture, design patterns, performance optimization, and application security.
• Experience supporting classified systems or national security customers.
• Experience leading technical efforts, owning major software components, or mentoring junior developers.
• Experience working directly with customers, users, testers, and mission stakeholders.

What We Are Looking For

We are looking for a capable software engineer who can take ownership of meaningful technical work, contribute to design decisions, and deliver reliable software in a complex mission environment.

The right candidate will understand more than how to write code. You should be able to evaluate requirements, make sound engineering decisions, troubleshoot across application boundaries, and collaborate effectively with the broader technical team.

This is a strong fit for a mid- to senior-level engineer who enjoys hands-on development, values quality and maintainability, and wants greater visibility into how their work supports the customer's mission. You will have the opportunity to make a direct technical impact while helping DPG strengthen its reputation as a trusted partner in Virginia.

About DPG Solutions

DPG Solutions provides mission-focused engineering, software development, DevSecOps, systems administration, and cleared technical support to national security customers. We focus on hiring strong mid- to senior-level engineers who can integrate quickly, solve real problems, and deliver value in complex mission environments.

Overview of Benefits

• Company-funded 401(k) Profit Sharing Plan: 25% of base pay deposited every pay period, vested on day one of employment
• All healthcare benefits and premiums paid by the company, including a company HSA contribution
• Annual performance bonuses
• 250 hours of PTO, with up to 40 hours available to carry over
• Biannual company-sponsored events for employees and their families
• Certification reimbursement and tuition reimbursement