Skip to main content
David Careers

Sr. Software Developer

Posted 3 days ago

system one holdingsGaithersburg (MD)
Software DevelopersComputer Systems Design Services

SENIORITY

Lead

Apply (opens in a new tab)

About the role

Senior Software Engineer
Location: Gaithersburg, MD
Schedule: Full Time
Work Arrangement: Onsite
Travel Required: NoShift: DayClearance Required: Active Top Secret/SCI with the ability to successfully complete a polygraph examination
Position Overview: We are seeking an experienced Senior Software Engineer to support the design, development, deployment, and maintenance of mission-critical enterprise applications. This position is ideal for a hands-on developer who enjoys solving complex technical problems, building reliable software, and collaborating within an Agile engineering environment. The Senior Software Engineer will work closely with product owners, architects, Scrum Masters, DevSecOps teams, and fellow developers to deliver secure, scalable, and maintainable software solutions.
Primary Responsibilities:
  • Design, develop, test, deploy, and maintain enterprise software applications using modern development practices
  • Develop clean, maintainable, and well-documented code that follows secure coding standards and engineering best practices
  • Design and implement RESTful APIs, microservices, and distributed application solutions
  • Participate in Agile ceremonies, including sprint planning, backlog refinement, daily stand-ups, sprint reviews, and retrospectives
  • Collaborate with product owners, architects, DevSecOps engineers, and development teams to deliver high-quality software
  • Develop automated unit, integration, and end-to-end tests to support application quality and reliability
  • Perform code reviews and provide technical guidance to junior developers
  • Troubleshoot complex application issues and perform root cause analysis
  • Collaborate with DevSecOps teams to support CI/CD pipelines and automated deployments
  • Optimize application performance, scalability, reliability, and security
  • Participate in architecture discussions, modernization initiatives, and technical roadmap planning
  • Support production deployments and resolve issues within mission-critical environments
Required Qualifications:
  • Active Top Secret/SCI clearance
  • Ability to successfully complete a polygraph examination
  • Bachelor's degree in Computer Science, Software Engineering, or a related field with 8 to 12 years of relevant experience, or a master's degree with 6 to 10 years of relevant experience
  • Eight or more years of professional software development experience
  • Strong hands-on proficiency in at least one object-oriented programming language, such as Java, C#, Python, or C++
  • Experience developing web-based applications or enterprise software solutions
  • Experience designing, developing, and consuming RESTful APIs
  • Experience working with relational databases, NoSQL databases, or both
  • Strong understanding of object-oriented design principles and software design patterns
  • Experience using Git or another distributed version control system
  • Experience working within Agile Scrum or SAFe development environments
  • Strong analytical, debugging, and problem-solving skills
  • Strong written and verbal communication skills
Preferred Qualifications:
  • Experience developing cloud-native applications using AWS, Azure, or another cloud platform
  • Experience with Docker, Kubernetes, or other container technologies
  • Experience designing or developing microservices architectures
  • Familiarity with DevSecOps practices and CI/CD tools such as Jenkins, GitLab CI, or Azure DevOps
  • Experience with Infrastructure as Code tools such as Terraform or Ansible
  • Experience with messaging technologies such as Kafka or RabbitMQ
  • Experience with React, Angular, Vue.js, or another modern front-end framework
  • Familiarity with Elasticsearch, Redis, or similar enterprise technologies
  • Experience following secure software development lifecycle practices
  • Security+ or another applicable DoD 8570/8140 aligned certification
Work Environment This is a full-time, onsite position based in Gaithersburg, Maryland. Candidates must be able to work onsite during normal daytime business hours. System One, and its subsidiaries including Joulé and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan. System One is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.

Before you apply

Applying takes about a minute. These four things decide how fast it moves after that.

Your profile is current

It's what we read first. Occupations, seniority and locations matter more than a long history.

Two examples you can talk through

Not a portfolio — just two pieces of work where you can explain the decisions and what you'd change.

A number in mind

What you're on now and what would make you move. We negotiate better when we know both.

Your notice period

Employers plan around it, and it's the question that stalls offers most often.

Once you apply, someone reads it and calls you before anything reaches the employer — usually within two working days.

More like this