Active Directory Specialist

Job Description:

L3 Engineer / SME – Active Directory (On‑Premise)

Experience:

10+ years

Domain:
Identity & Access Management, Windows Infrastructure

We are looking for a highly skilled L3 Active Directory (On‑Premise) SME with deep experience in designing, managing, and troubleshooting complex AD environments. The candidate will be the highest escalation point for AD issues, lead architectural improvements, perform RCA, and ensure AD security, availability, and performance in a large enterprise environment.

Serve as the top‑tier escalation for Active Directory and Windows infrastructure issues.

Troubleshoot complex authentication, replication, DNS, GPO, policy processing, and trust issues.

Perform advanced RCA, log analysis, and performance debugging.

Develop L3 SOPs, KB articles, scripts, and automation for operations teams.

Oversee FSMO roles, domain controllers (DC health), AD sites, replication topology.

Install, upgrade, and harden domain controllers (physical/virtual).

Implement AD schema updates, forest/domain functional level upgrades.

Perform AD migration, consolidation, restructuring, and domain/forest trust design.

Troubleshoot AD-integrated DNS issues (zones, scavenging, forwarding, delegation).

Manage and secure DHCP scopes, reservations, failover.

Deep understanding of Kerberos, NTLM, LDAP, LDAPS, SPNs, tickets, token bloat.

Ensure GPO performance tuning, inheritance control, WMI filters, controlled rollouts.

Implement AD security baselines, CIS benchmarks, and Microsoft security best practices.

Periodically audit domain controllers, replication, delegations, privileged groups.

Manage tiered admin model, least privilege, Just‑In‑Time (JIT) & Just‑Enough‑Administration (JEA).

Enforce password policies, PAM/Privileged Identity controls, and secure service account management.

Perform logs and event analysis through SIEM (Splunk, Sentinel, QRadar).

Build and validate disaster recovery procedures for AD, DNS, and DHCP.

Maintain backup/restore strategies using tools like AD Recycle Bin, Authoritative Restore, System State, VM snapshots.

Ensure site resiliency, replication health, and multi‑site availability.

Automate AD operations using Power Shell (mandatory).

Build scripts for:

Group management

GPO backup/restore

ACL/permissions

Health monitoring & reporting

Expertise integrating AD with:

ADFS

SSO solutions

LDAP‑based applications

PKI/Certification Services

Understand hybrid identity dependencies (even though this role is on‑prem focused).

10–12+ years hands‑on experience in enterprise Active Directory environments.

Deep knowledge of:

DNS, DHCP, Sites & Services

Kerberos, LDAP, GPO, trusts, replication

Experience implementing AD hardening, security baselines, RBAC delegation.

Knowledge of backup/restore and DR strategies for domain controllers.

Strong understanding of networking fundamentals (TCP/IP, firewall rules, ports).

Experience with Azure AD and hybrid identity models.

Experience with IAM/PAM tools (Delinea, Cyber Ark, Beyond Trust).

Familiarity with virtualization (VMware/Hyper‑V).

Experience with enterprise SIEM and security monitoring tools.

• Design, implement, and maintain enterprise Active Directory infrastructure.
• Manage Domain Controllers, Global Catalogs, FSMO roles, Sites and Services, and AD Replication.
• Perform Domain Controller promotions, demotions, migrations, and health validations.
• Troubleshoot complex AD replication, authentication, Kerberos, DNS, LDAP, and Group Policy issues.
• Administer Active Directory objects including Users, Groups, Computers, Organizational Units (OUs), and Trusts.
• Manage Group Policy Objects (GPOs), security baselines, and policy troubleshooting.
• Design, deploy, and troubleshoot Group Policy Objects (GPOs) for enterprise-wide policy management.
• Support Microsoft Entra  (Azure AD), Azure AD Connect, and Hybrid Identity environments.
• Perform forest and domain upgrades, schema extensions, and disaster recovery…