Principal Systems Engineer (API Gateway) - TS/SCI w CI Poly

Modern Government Solutions•Sterling, VA

5d•Onsite

About The Position

Modern Government Solutions (MGS) is seeking a Principal Systems Engineer to architect, integrate, and secure mission-critical API ecosystems supporting next-generation national security capabilities. The role leads the design and implementation of API gateway solutions, cloud-native integrations, and enterprise service architectures that enable secure data exchange across complex environments. The engineer works with software engineers, cloud architects, cybersecurity professionals, and mission stakeholders to modernize critical systems through scalable APIs, automation, and cloud technologies. The position requires deep expertise in API platforms, cloud architecture, systems integration, and troubleshooting complex enterprise environments while maintaining the engineering rigor needed for high-impact mission operations. This is a full-time, onsite position in Sterling, Virginia. Relocation assistance may be considered. An active TS/SCI clearance with CI Polygraph is required.

Requirements

Active DoD TS/SCI security clearance with CI Polygraph.
Must meet DoD 8140 requirements, including Security+ CE certification.
Bachelor's degree in Systems Engineering, Computer Science, Computer Engineering, Software Engineering, Information Technology, Electrical Engineering, Mathematics, Physics, or a related field.
16+ years of experience designing, integrating, and supporting enterprise systems, cloud architectures, and API-driven solutions within complex mission environments.
5+ years of experience implementing and administering API gateway technologies in cloud-based architectures.
Experience designing secure APIs and enterprise integration solutions using REST, GraphQL, event-driven architectures, message queues, streaming platforms, or ETL pipelines.
Experience supporting Windows-based platforms, COTS applications, and cloud environments utilizing AWS or Azure.
Experience developing software, automation, or integration solutions using Java, Python, C#, or similar programming languages.
Demonstrated expertise in testing, validation, troubleshooting, root-cause analysis, and technical documentation.
Applicants selected will be United States citizens and may be subject to a government security investigation for access to classified information.

Nice To Haves

Experience supporting Broadcom API Gateway, MuleSoft, Apigee, or similar API management platforms.
Experience designing and implementing service mesh architectures using Istio, Linkerd, or similar technologies.
Experience optimizing cloud-hosted solutions and supporting Google Cloud Platform (GCP), Oracle Cloud Infrastructure (OCI), IBM Cloud, or similar technologies.
Experience implementing ServiceNow integrations and supporting customer security requirements within classified environments.
Experience supporting virtualization technologies, application streaming, cloud-native architectures, and enterprise integration platforms.

Responsibilities

Design, implement, and sustain enterprise API gateway solutions and service architectures supporting secure system integration across mission environments.
Architect and support cloud-based integrations using APIs, message queues, streaming platforms, ETL pipelines, and related technologies.
Support Windows-based platforms, COTS applications, and cloud-hosted systems within secure enterprise environments.
Troubleshoot complex application, infrastructure, and integration issues; perform root cause analysis and implement corrective actions.
Develop and execute system testing, validation, and performance assessment activities to ensure operational readiness and reliability.
Collaborate with engineering, cybersecurity, infrastructure, and mission stakeholders to implement technical solutions and architectural improvements in a Scaled Agile Framework environment.
Participate in Program Increment and Sprint planning, including t-shirt sizing, story point estimation, and dependency mapping.
Evaluate emerging technologies and recommend enhancements to API platforms, cloud architectures and infrastructure configurations, and enterprise integration capabilities.
Create and maintain technical documentation, architecture artifacts, implementation guides, and operational procedures.
Provide technical leadership and engineering guidance across API platform, cloud, and integration initiatives.
Remain in a stationary position for extended periods while working at a computer workstation.
Communicate effectively with customers, team members, and stakeholders in written and verbal formats.