Senior Slack Software Engineer Jobs in Washington

Senior Software Engineer — Secure Mission Systems

Location: Mainly remote, with onsite work in Laurel, Maryland, typically one day approximately every six weeks for team-wide sprint planning
Clearance: Active final DoD Secret clearance required

Build Secure Software for High-Impact Defense Missions

Rackner is seeking a Senior Software Engineer to design, build, test, and deliver secure mission-planning and decision-support software for a Department of Defense customer.

This role gives you broader ownership than a traditional feature-development position. You will contribute across application engineering, secure CI/CD, containerized deployment, automated testing, cybersecurity remediation, and AI-capability integration. You will work alongside experienced technical teams and help move complex software from design through secure delivery.

This position is contingent upon contract award and final customer approval.

What You Will Do

• Design, develop, test, and integrate new software capabilities.
• Build and maintain secure CI/CD workflows using GitLab and related development systems.
• Support containerized application deployment through OpenShift and Kubernetes.
• Apply secure software-development lifecycle practices throughout delivery.
• Integrate AI models and support capabilities involving LLM assistants, retrieval-augmented generation, and agentic AI.
• Develop unit, integration, and system-level tests.
• Use automated security tools such as Fortify, JFrog Xray, and OWASP ZAP.
• Investigate vulnerabilities and support cybersecurity remediation.
• Participate in code reviews, technical reviews, and solution-design discussions.
• Create software-design documents, sequence diagrams, workflow descriptions, and test reports.
• Communicate progress, blockers, risks, and schedule concerns to technical and program stakeholders.
• Collaborate with customer technical leads in remote and onsite settings.

What You Will Bring

• Bachelor's degree in Computer Science or a related field
• 10+ years of software engineering experience, including hands-on design, development, testing, or integration work
• Hands-on experience with CI/CD, Kubernetes, GitLab, and OpenShift
• Strong understanding of secure software-development lifecycle practices
• Experience using Fortify and/or JFrog Xray for automated security scanning and vulnerability remediation
• Integrating AI models or AI-enabled capabilities into software applications
• Building automated unit and integration tests
• Clear technical documentation and stakeholder communication skills

Helpful Experience

• OWASP ZAP or comparable application-security testing tools.
• Artifactory or similar artifact-management platforms.
• LLM assistants, retrieval-augmented generation, or agentic-AI components.
• Jira, Confluence, and Slack in a structured development environment.
• Software delivery supporting defense, national-security, or other regulated missions.
• Customer-provided development systems and secure internal networks.

Why Rackner

At Rackner, you will have the opportunity to build technology that supports critical defense and public-sector missions.

You will work on more than isolated coding tickets or pipeline tasks. This role brings together hands-on application development, secure software delivery, container platforms, automated testing, cybersecurity, and emerging AI capabilities.

Rackner has delivered more than $30 million in recent federal awards and supports mission-critical work across defense, civilian, and public-sector environments. We are looking for a senior software engineer who can help build on that momentum by delivering reliable software, strengthening security, and helping teams move complex mission capabilities forward.

Benefits & Professional Growth

• Competitive compensation
• Company-supported certifications aligned with current and future program work
• 401(k) with 100% company match up to 6%
• Medical, dental, vision, life, and disability coverage
• Paid time off and company holidays
• Remote-work support and home-office equipment plan
• Fitness and wellness reimbursement
• Weekly pay schedule
• Professional-development and future growth opportunities

Apply

If you are a senior software engineer who wants broader ownership across secure application development, container platforms, DevSecOps, software assurance, and AI integration, we would like to hear from you.