SumasEdge Corporation

You would implement enterprise certificate renewal automation, build and secure an OT Active Directory environment, troubleshoot directory services, and create operational documentation. | The role requires 10+ years of enterprise Active Directory experience, advanced AD DS and DNS troubleshooting, PowerShell, and expert SSL/TLS and PKI knowledge; Sectigo and regulated-environment experience are preferred. | Job Title:- Senior Active Directory Engineer Location:- Tarrytown, NY (Remote/Need local who can go onsite when needed) Duration:- Contract Job Description Overview Seeking two Senior Active Directory Engineers to support Directory Services initiatives, including certificate renewal automation through Sectigo Certificate Manager and deploying a dedicated OT Active Directory Test/POC environment. Engineers will execute against architecture documents and standards provided by the internal AD Architecture and Operations teams. Responsibilities • Implement certificate lifecycle and renewal automation using Sectigo Certificate Manager. • Configure auto-renewal policies and onboard Windows servers, IIS applications, Linux hosts, load balancers, network appliances, and OT systems. • Coordinate with application and infrastructure teams to test and validate certificate renewal workflows. • Build a new OT AD forest, domain, and domain controllers based on the provided architecture. • Configure AD Sites & Services, replication, DNS, Group Policy, OU structures, delegation, and service accounts. • Apply domain controller security baselines, Tier-0 controls, and privileged access restrictions. • Support AD administration, advanced troubleshooting, operational readiness testing, and root cause analysis. • Produce configuration documentation, installation logs, runbooks, operational guides, handover materials, and weekly status reports. • Follow established change-control procedures and support additional Directory Services initiatives as needed. Required Experience • 10+ years of enterprise Active Directory experience, including large, multi-site environments. • Hands-on AD DS deployment, domain controller builds/upgrades, promotion/demotion, SYSVOL/DFS-R, and FSMO management. • Strong AD replication and Sites & Services troubleshooting using tools such as dcdiag and repadmin. • Deep knowledge of AD-integrated DNS, SRV records, zone troubleshooting, and DNS security. • Strong LDAP, Kerberos, authentication troubleshooting, and Group Policy experience. • Experience supporting Windows Server 2016, 2022, and 2025, including hardening and security baselines. • Strong PowerShell scripting and automation skills. • Expert-level SSL/TLS and PKI experience required, including certificate lifecycle management, certificate chains/trust, installation, renewal automation, and advanced troubleshooting across servers, applications, and network devices. Sectigo Certificate Manager experience preferred. • Working knowledge of Sectigo Certificate Manager or comparable enterprise certificate management tools. • Understanding of Microsoft’s tiering model, credential hygiene, and privileged access restrictions. • Ability to execute independently, follow detailed architecture standards, and produce thorough engineering documentation. Preferred Experience • Pharmaceutical industry experience is highly preferred. • Experience in GxP or other regulated, change-controlled environments. • OT Active Directory environments and familiarity with OT security constraints. • Direct experience implementing Sectigo certificate renewal automation.