Principal Software Engineer

Leidos is hiring a TS/SCI cleared Principal Software Engineer to support the DIA-NDOC DOMEX Technology Platform (DTP) contract. This onsite role in Bethesda, MD focuses on building reliable, observable, and secure software. You’ll design and deliver Python microservices deployed on Kubernetes, integrating Kafka for messaging and Elasticsearch for real-time and batch indexing and querying.

Leidos offers health and wellness programs, income protection, paid leave, and retirement. The pay range for this position is USD 131,300 - 237,350 per year.

Responsibilities

• Design, develop, test, and maintain Python microservices for production environments
• Implement message consumers and producers using Apache Kafka
• Integrate Elasticsearch for real-time and batch data indexing and querying
• Write unit and integration tests and drive high code coverage and reliability
• Build CI/CD pipelines and deploy services into Kubernetes clusters
• Support design discussions, code reviews, and architecture planning
• Monitor and troubleshoot production issues using observability tools
• Contribute to technical documentation and knowledge sharing
• Use appropriate software engineering and design methodologies for development, integration, and production
• Foster collaboration across team members to deliver quality service and product to customers

Requirements

• Bachelor’s Degree and 12+ years of prior relevant experience, or Masters with 10+ years; relevant experience may be considered in lieu of a degree
• Active Top Secret/SCI clearance and ability to obtain and maintain a Polygraph
• Proficiency in Python and backend frameworks such as FastAPI or Flask
• Experience with containerization, especially Docker
• Experience with ETL (Extraction, Transformation, Load)
• Hands-on development in Linux, including bash or bash-like scripting
• Strong understanding of RESTful APIs and microservice architecture
• Hands-on experience with Kubernetes, including deploying, monitoring, and debugging services
• Understanding of design patterns, security practices, and logging/monitoring principles
• Familiarity with Git and collaborative workflows (PRs and reviews)
• Experience with DevOps practices and CI/CD tools, especially Gitlab or Jenkins
• Strong verbal and written communication skills
• Experience with Agile practices
• Ability to work well in a team and act as a self-starter

Technologies

Python, FastAPI, Flask, Apache Kafka, Elasticsearch, Kubernetes, Docker, Linux, bash, RESTful APIs, Git, CI/CD, Gitlab, Jenkins, ETL.

Additional skills that would be a plus

• Experience designing and implementing software development kits
• Familiarity with DGX (Deep GPU Xceleration)
• Active Security+ certification and ability to obtain Privileged User Account (PUA) certification by the Government
• Elasticsearch certifications or other related stack certifications
• Experience with production or enterprise systems at scale
• Knowledge of distributed systems concepts such as idempotency and eventual consistency
• Familiarity with schema registries and Kafka streaming patterns
• Experience blending analytical methodologies and leveraging COTS/GOTS/OS tools in unconventional ways
• Experience with Amazon Web Services (AWS/C2S)
• Familiarity or experience building applications around Large Language Models and Agentic AI

Work model

Most work is conducted on-site at the client location in Bethesda, MD. Leidos also offers a flexible schedule, and remote work may vary based on client requirements and deliverables.

Original posting date: September 22, 2026.

U.S. positions: Leidos reasonably anticipates this job requisition will remain open for at least 3 days, with an anticipated close date no earlier than 3 days after the original posting date.