MANTECH seeks a motivated, career and customer-oriented Senior Active Directory & PKI Service Engineer to join our team working in Crane, IN. This is a fulltime onsite position.Responsibilities include but are not limited to:Design, implement, maintain, and support enterprise Microsoft Active Directory (AD) environments.Support enterprise network services by administering and optimizing GPO design, DNS, DHCP, and Windows Enterprise PKIManage and support Public Key Infrastructure (PKI), including digital certificate issuance and validation across hybrid environments.Enhance and secure identity infrastructures through authentication, authorization, and access control policies.Troubleshoot and resolve issues related to domain services and directory integration.Collaborate with IT security and infrastructure teams to strengthen enterprise identity management and compliance.Apply understanding of authentication protocols such as Kerberos, LDAP, and SAML to enhance secure system access and identity managementOperate in hybrid IT environments, integrating and supporting both on-premises infrastructure and cloud-based systems to meet mission and operational goalsMinimum Qualifications:High school diploma or equivalent7+ years of systems administration or related experienceMust have demonstrated experience in both active directory and PKI service administrationMust possess one of the following certifications: CASP+, CISSP, or equivalent DoD 8570 baseline IAT 3 certificationPreferred Qualifications:Bachelor’s degree in an IT related fieldMicrosoft Certified: Identity and Access Administrator Associate, or equivalent.Demonstrated expertise in Active Directory architecture and administration.Clearance Requirements:Must be a U.S. Citizen and have the ability to obtain and maintain a Secret security clearance.Candidate will be required to obtain an interim Secret clearance before onboarding Physical Requirements:The person in this position must be able to remain in a stationary position 80% of the time.Occasionally move about inside the office to access file cabinets, office machinery, or to communicate with co-workers, management, and customers, via email, phone, and or virtual communication, which may involve delivering presentations.