We are seeking an experienced Senior Software Engineer with a strong backend focus and full-stack capabilities to design, build, test and maintain scalable software systems. This role will play a key part in architecting backend services, developing APIs, and collaborating with development team to deliver reliable, high-performance applications. The ideal candidate has deep experience in backend systems, cloud-native architectures, testing, and modern CI/CD practices and tools, while also being comfortable contributing across the full stack when needed. Key Responsibilities: • Design and develop scalable backend services, APIs, and microservices. • Create and maintain full-scale testing architecture plans and system design for software application. • Build, test, and maintain high-performance, secure, and reliable applications. • Collaborate with product managers, designers, customers, and engineers to deliver new features. • Write clean, maintainable, well-tested code following best practices. • Review code and mentor junior engineers. • Optimize applications for performance, scalability, and reliability. • Support CI/CD pipelines and cloud infrastructure for application. • Participate in Agile ceremonies including sprint planning, standups, retrospectives, and PI planning events. • Troubleshoot production issues and implement long-term solutions. • Functions as a technical expert across multiple project assignments. Required Qualifications: • Bachelor’s degree in Computer Science, Software Engineering, related field, or equivalent experience. • 12–15+ years (or 10-13 years with Master’s Degree) of professional software development experience. • Strong backend development experience in languages such as: • Java • Spring Boot • Hibernate • Hibernate using native queries • Strong automated testing experience in end-to-end testing, regression testing, integration testing, etc. • Experience building RESTful APIs and microservices architectures. • Strong knowledge of relational databases (PostgreSQL, MySQL, etc.) • Experience with cloud platforms such as AWS, Azure, or Google Cloud. • Experience with agile project management software such as Jira, Confluence, etc. • Familiarity with containerization technologies like Docker and Kubernetes. • Experience with version control systems such as Git. • Experience with CI/CD pipelines such as Gitlab. • Strong understanding of software architecture, design patterns, and system scalability. Preferred Qualifications: • Experience with frontend frameworks (React, Angular, or Vue). • Knowledge of infrastructure-as-code tools (Terraform, CloudFormation). • Experience with observability tools (Datadog, Prometheus, Grafana). Key Competencies: • Strong problem-solving and analytical thinking. • Passion for quality control and improving engineering practices. • Excellent communication and collaboration skills. • Ownership mindset and accountability for deliverables. If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares. Original Posting: August 21, 2026 For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above. Pay Range: Pay Range $131,300.00 - $237,350.00 The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.