**Description**

Leidos is seeking an experienced **Senior Mechanical Engineer** to support critical national security missions in Reston, Virginia. This role focuses on the assessment, reverse engineering, and characterization of complex above-ground and subterranean facilities located in denied-access environments.

The successful candidate will leverage strong engineering expertise to analyze facility designs, spatial layouts, operational workflows, and supporting infrastructure to determine functional capabilities and mission relevance. You will evaluate facility systems, model critical infrastructure, identify vulnerabilities, and provide technical insights that support complex intelligence and defense initiatives.

This position requires an innovative engineer who can develop sound technical assessments in situations where complete information is inherently unavailable. The ideal candidate combines creativity, analytical rigor, and exceptional attention ...