Domain Services Engineer - Top Secret

Domain Service EngineerGDIT is seeking a Domain Service Engineer to support the planning, building, and operations of a large, globally accessed, hybrid cloud computing system. The Domain Services Engineer provides support, implementation, and design services for ISE and Microsoft Active Directory and Windows-based systems across the enterprise, including directory and identity management solutions.We are looking for an individual who will serve as our internal Domain Services team a broad scale of technologies, working with 802.1X network access control using Cisco Identity Services Engine (ISE), while simultaneously taking ownership of our core DDI (DNS, DHCP, and IPAM) services. Beyond day-to-day administration and Tier 3 engineering, this individual will play a vital role in designing, modernizing, and documenting system-level architectures to ensure our hybrid on-premises and cloud infrastructures are highly available, secure, and scalable. The ideal candidate will be a motivated self-starter with excellent written and verbal communication skills, who exceeds as an individual, as well as excels among peers in a team environment.Job duties include but are not limited to:Accountable for the management, uptime, and lifecycle of the organization's 802.1x architecture.Deliver and implement a secure, scalable, and resilient Active Directory design, following industry best practices while adhering to Information Security standards.Provide SME level assistance and escalation support for all troubleshooting tasks related to DNS, DHCP, and AD, including but not limited to integration with Windows and non-Windows endpoints, authentication, role-based access controls, DNS, DHCP, etc.Manage the environment proactively, anticipating risks and issues, designing and engineering for resiliency. Take technical ownership of projects and systems accordingly.Facilitate the implementation of Group Policy Objects (GPO) based on stated requirements. Troubleshoot and resolve any GPO related issues that arise.Monitor and identify replication interruptions between domain controllers, DNS and DHCP Server configurations.Management of the Public Key Infrastructure (PKI) systems and certificates.Required qualifications:5+ years of experience in progressive roles from Active Directory Administrator to Sr. EngineerKnowledge of at least scripting languages (e.g. Powershell, Python, Bash, or Perl).In depth understanding of Active Directory or LDAP authentication and administration.Advanced familiarity with enterprise directory synchronization tools such as Azure Active Directory Connect, Cisco Directory Synchronization, or others.Implement and Manage enterprise-wide architecture, deployment, and ongoing administration of Cisco ISEMaintain advanced network access control (NAC) policies, utilizing 802.1X, MAC Authentication Bypass (MAB), and Web Authentication.Act as a Tier 3 escalation point for complex 802.1X/RADIUS authentication issues, certificate mismatches, and supplicant-side issues across Windows, macOS, Linux, and IoT devices.Preferred qualifications:An analytic mindset with the ability to define complex infrastructure problems, correlate logs across multiple systems (ISE, AD, DNS, Network Switches), and execute systematic resolutions.Someone who looks beyond immediate triage to design architectures that prevent future systemic failures.A strong capability to translate highly technical concepts to non-technical business stakeholders, and collaborate across siloed Network, Systems, and Security teams.Configure and optimize network device profiling, Cisco TrustSec (Security Group Tags), and Comply-to-Connect (C2C) architectures.Integrate Cisco ISE with Active Directory, Azure AD/Entra ID, PKI/Certificate Authorities, and SIEM tools for automated threat containment and compliance reporting.Evaluate existing infrastructure pipelines and propose architectural modernizations to leverage Zero Trust Network Architecture (ZTNA), automation, and hybrid-cloud capabilities.Architect, document, and present system-level designs that integrate on-premises systems, virtualization platforms, and public/private cloud environments.Experience working in a fast tempo government agency production IT environment.Experience troubleshooting various Microsoft Windows Server platforms' roles and features.Location: Customer Site / NGA Washington or NGA St. LouisUS Citizenship Required