General Overview APEX TK is seeking a Model-Based Systems Engineer (MBSE) to support the Targets and Countermeasures program office of the Missile Defense Agency (MDA). In this role, you will apply systems engineering principles within a digital engineering framework to create, analyze, and maintain system architecture models. You will collaborate with government leads, prime contractors, and cross-functional engineering teams to trace requirements, model behavioral and structural architectures, and support technical baseline reviews. What You'll Be Doing: • System Modeling & Architecture: Develop and maintain descriptive system models using SysML to capture system behaviors, structure, interfaces, and operational requirements across MDA programs. • Requirements Traceability: Map system-level and component-level requirements directly to architecture artifacts, ensuring end-to-end traceability, verification matrices, and baseline integrity. • Digital Engineering Integration: Support the implementation of MDA Digital Engineering initiatives by linking MBSE models with external tools, simulations, and data repositories. • Technical Baseline Reviews: Assist in preparing and presenting model-centric artifacts for major program milestone reviews (e.g., SRR, PDR, CDR, CCBs). • Interface & Trade Studies: Conduct architectural trade studies, analyze interface definition documents (IDDs/ICDs), and model system interfaces to identify gaps and resolve integration risks. • Configuration & Data Management: Maintain version control and configuration baseline compliance for SysML models in accordance with program data management standards. What Required Skills You'll Bring: • Security Clearance: Active DoD Secret clearance • Education & Experience: Bachelor degree with 7+ years supporting missile defense or large-scale, complex DoD programs. • Technical Proficiency: • Demonstrated proficiency with SysML (Systems Modeling Language) and core systems engineering frameworks (DoDAF, UAF). • Hands-on experience with industry-standard MBSE modeling tools (e.g., Cameo Systems Modeler / Cameo Enterprise Architect, MagicDraw, Sparx Enterprise Architect). • Communication: Ability to distill complex system architectures into clear, concise diagrams, technical documentation, and briefings for multidisciplinary stakeholders. What Desired Skills You'll Bring: • Experience supporting MDA programs (e.g., Targets and Countermeasures, Ground-Based Midcourse Defense, THAAD, Aegis BMD, or C2BMC). • OMG-Certified Systems Modeling Professional (OCSMP) certification (Fundamental, Intermediate, or Advanced). • Working knowledge of requirement management tools (e.g., DOORS, Cameo Requirements Plugin) and issue-tracking platforms (Jira, Confluence). • Experience integrating MBSE models with analytical/simulation environments (e.g., MATLAB/Simulink, Python, or OpenMBEE). • Familiarity with DoD Systems Engineering processes, CDRLs, and technical baseline governance.