About Adelphi: Adelphi builds AI/ML-enabled secure data access and sharing technology for the U.S. intelligence and defense communities, using its Connector software product to enable federated data discovery that cuts intelligence-sharing time from months to minutes. The company's mission is to eliminate data silos, build trust in automation without compromising security, and improve information flow across mission-critical environments. Adelphi closed a $7M Seed round in August 2025 and has Customers across the Intelligence Community and the Department of War. About the Role: As Adelphi’s first ISSM, you will own the security program for Adelphi. You will drive Adelphi’s work through Dept of War authorization on the IL2 (NIPR) path and onto a defensible IL5 trajectory, operating on a continuous-ATO cadence that matches our weekly sprint pace. This role sits at the intersection of security architecture, compliance program management, and day-to-day security operations. You will be the primary interface to the Dept of War Authorizing Official, assessors, and our customer program office, while working shoulder-to-shoulder with a small, high-velocity engineering team. Clearance Requirement: Active Top Secret/SCI Is this you? * Security Program Ownership: You've owned a government security program end-to-end, from initial authorization through continuous monitoring, and know how to keep it moving inside a fast-paced engineering team without becoming a bottleneck. You have personally led at least one DoD or IC system through the NIST RMF authorization process to an ATO and sustained it through continuous monitoring. Prior ISSM or ISSO experience on a DoD or IC contract is required; experience as a Prime contractor is strongly preferred. * Experience: 8+ years in cybersecurity, information assurance, or security engineering, with a substantial portion directly supporting DoD or IC systems. You have a track record of delivering this work reliably and under scrutiny. * Security Architecture & Technical Depth: You think at the architecture level across identity, authorization, cryptography, and audit. You've worked in environments where the security boundaries between systems matter, and you know how to design for them deliberately. Experience with FedRAMP inheritance modeling and CSP shared-responsibility mapping is a plus. * Agentic AI & Emerging Tech: You're familiar with how AI agents interact with data and tools, and you've thought seriously about what securing those interactions looks like, even if the specific stack is new to you. Familiarity with Palantir Foundry, O365/SharePoint, or Databricks in classified or IL5 environments is a bonus. * Security Operations & Incident Response: You've run security operations and led incident response in complex environments. You write clear, structured findings for both technical and executive audiences. * Stakeholder Management: You've been the primary security interface to government customers, assessors, and internal engineering leadership, and you know how to manage all of them at once. * Certifications: A current DoD 8140 / 8570 IAM-qualifying certification is required at hire. CISSP or CISM (IAM Level III) strongly preferred; CASP+ accepted. You must be able to maintain certification currency throughout the role. * Bonus points if you have prior experience standing up a security program at a startup or small company Benefits: * Healthcare coverage: 100% employee premium and 50% dependents premium coverage of a platinum-level plan. * 401K with 2% company match. * $500 monthly Physical and Mental Health reimbursement program. * Unlimited time-off policy. * Competitive salary and equity compensation. * Opportunity to work on impactful projects in the national security sector. * Career growth and leadership opportunities in a dynamic, innovative environment.