Infrastructure Engineer

Salary: £130,000 - 137,800 per year

Requirements:

• Extensive hands-on experience administering enterprise Active Directory environments.
• Strong knowledge of Active Directory Domain Services (AD DS), Active Directory Sites and Services, forest and domain administration, DNS, Group Policy, LDAP/LDAPS, Kerberos authentication, trusts, replication, and AD backup and recovery.
• Experience troubleshooting complex authentication and directory service issues.
• Strong experience administering Microsoft Active Directory Certificate Services (AD CS).
• Experience managing Certificate Authorities, Certificate Templates, CRL and AIA infrastructure, certificate lifecycle management, certificate enrolment services, and key recovery and archival.
• Experience supporting enterprise PKI environments.
• Windows Server 2016/2019/2022 administration experience.
• PowerShell scripting and automation experience.
• Experience with security hardening and privileged administration.
• Experience with high availability and disaster recovery planning.
• Experience with infrastructure monitoring and operational support.
• Working knowledge of Microsoft Entra ID, Microsoft Entra Connect / Cloud Sync, Microsoft Identity Manager (MIM), Okta, and BeyondTrust.
• Understanding of Identity and Access Management (IAM), Joiner-Mover-Leaver processes, identity lifecycle management, authentication and authorisation, access governance, and role-based access control (RBAC).
• Clearance required: BPPS.
• Ability to work onsite 5 days per week in Manchester or Inverness.

Responsibilities:

• Administer and maintain enterprise Active Directory forests, domains, and domain controllers.
• Manage Active Directory Sites and Services, replication topology, trusts, and directory services infrastructure.
• Administer AD-integrated DNS and support authentication services across the enterprise.
• Manage and maintain Group Policy architecture, including policy design, implementation, troubleshooting, and lifecycle management.
• Support Active Directory backup, recovery, disaster recovery, and business continuity processes.
• Monitor platform health, performance, security, and replication.
• Support Active Directory upgrades, migrations, consolidation projects, and infrastructure improvements.
• Implement and maintain Active Directory security hardening standards and privileged access controls.
• Administer and support Microsoft Active Directory Certificate Services (AD CS).
• Manage Certificate Authorities, certificate templates, certificate enrolment, and certificate lifecycle processes.
• Support Offline Root CA and Issuing CA infrastructure.
• Administer Certificate Revocation Lists (CRL), Authority Information Access (AIA), and certificate distribution services.
• Monitor certificate compliance, renewals, revocations, and expiration management.
• Maintain PKI operational documentation, recovery procedures, and security standards.
• Support cryptographic and certificate-related troubleshooting across infrastructure and security platforms.
• Support Microsoft Entra Connect and hybrid identity infrastructure.
• Maintain LDAP, LDAPS, Kerberos, and NTLM authentication services.
• Support integrations between Active Directory and enterprise identity platforms including MIM, Entra ID, Okta, and BeyondTrust.
• Assist with identity-related service improvements and platform optimisation initiatives.
• Support authentication, directory, and identity infrastructure incidents through to resolution.
• Work collaboratively with the IDAM engineering team to support critical identity lifecycle services.
• Provide L2/L3 support for identity-related incidents and service requests.
• Assist with troubleshooting user provisioning, synchronisation, and authentication issues.
• Support MIM, Entra ID, Okta, and BeyondTrust integrations where infrastructure expertise is required.
• Collaborate with IDAM engineers to investigate root causes and implement long-term solutions.
• Support operational activities across the wider identity ecosystem during periods of increased demand.
• Develop and maintain PowerShell automation for identity infrastructure administration.
• Drive service improvements, platform optimisation, and operational efficiencies.
• Contribute to security improvement initiatives, vulnerability remediation, and infrastructure modernisation.
• Produce and maintain technical documentation, operational procedures, and support runbooks.

Technologies:

• Active Directory
• Cloud
• IAM
• Support
• LDAP
• PowerShell
• RBAC
• Security
• Windows
• DevOps

More:

We are seeking an experienced Senior Identity Infrastructure Engineer to support and maintain the core identity infrastructure platforms that underpin our Identity and Access Management (IDAM) services. This is a 6-month contract role based in secure facilities in Manchester or Inverness, with 5 days onsite required and a rate of up to £530 per day on an umbrella basis. We work closely across security, engineering, and IDAM teams to ensure the availability, resilience, and security of critical identity platforms, and we value strong expertise in Microsoft Active Directory, PKI, and enterprise authentication services. Suspicious outreach claiming to be from us should be verified via the ManpowerGroup website.

last updated 32 week of 2026