Senior IT Infrastructure Administrator, Security

About the Role

Hands‑on infrastructure security role with real ownership and visible impact. We’re looking for a senior infrastructure professional who enjoys solving practical security challenges and improving how security is delivered across enterprise systems. The role sits within the IT Infrastructure team and works closely with Cybersecurity, with a strong focus on implementation, remediation, and secure operations across Windows and Linux environments.

This is not a purely advisory or monitoring position. You’ll take direct ownership of vulnerability remediation, help improve patching cycles, and ensure systems are securely configured and operationally resilient. You’ll also contribute to key initiatives including certificate lifecycle management and the operational use of security platforms such as Privileged Access Management and Cloudflare.

If you enjoy hands‑on work, broad technical exposure, and the opportunity to improve security posture in a meaningful way, this is a role where you can make a clear and measurable difference.

• Take ownership of vulnerability remediation across enterprise systems, helping reduce backlog and improve remediation delivery at scale.
• Improve patching cadence, configuration hygiene, and secure operational practices across infrastructure environments.
• Administer and harden Windows Server environments, including Active Directory, Group Policy, DNS, authentication, and certificate services, with supporting Linux administration.
• Support certificate lifecycle management, including TLS/PKI, renewals, and ongoing certificate operations.
• Work with core security platforms such as PAM solutions and Cloudflare, and support logging and monitoring platforms such as Sumo Logic or Splunk.
• Partner closely with Cybersecurity and infrastructure stakeholders to implement approved controls, remediate findings, and improve how security is operationalized across environments.

• 8+ years of experience in enterprise systems administration or IT infrastructure.
• Strong generalist infrastructure background with the ability to work across multiple systems and environments.
• Hands‑on experience with Windows Server (Active Directory, DNS, authentication, certificates) and working knowledge of Linux administration.
• Experience managing certificate lifecycle (TLS/PKI), including renewal and ongoing management.
• Exposure to security tools such as Privileged Access Management (PAM) and Cloudflare (WAF/edge security).
• Experience with logging/monitoring platforms (e.g., Splunk, Sumo Logic or similar).
• Proven ability to remediate vulnerabilities hands‑on, including patching and reducing backlog across systems.
• Strong scripting/automation skills (Power Shell required).
• Ability to apply security controls across infrastructure and prevent misconfigurations.

• Experience automating certificate lifecycle processes across environments.
• Exposure to SIEM or centralized logging beyond administration, including tuning, alerting, or optimization.
• Experience delivering infrastructure or security projects end‑to‑end.
• Experience working in SaaS or cloud‑centric environments.
• Ability to produce technical documentation, runbooks, and support knowledge transfer.

Generous Time Off packages, including additional half days with each public holiday in your location.

Global career development opportunities.

Social events.

Referral bonus scheme – up to $3,000 per successful referral.

Plus many more benefits.

Integrity:
Face reality with honesty, courage and accountability.

Imagination:
Deal creatively with challenges and envision what the world could be.

Discipline:
Build good habits into reflexes which become a part of our life.

Service:
Committed to the success of others.

Applicants must be within a commutable distance (within 2 hours or 80 miles) of one of the listed offices.

Pre‑Employment Screening Disclaimer:
As part of our recruitment process, we carry out identity checks on all candidates. Offers of employment are conditional upon the completion of satisfactory background checks prior to the commencement of work. These checks may include verification of identity, right to work in the UK, employment history, and other relevant pre‑employment screening. Please note that additional checks may be required depending on the nature of the role and the jurisdiction in which the role is based or operates.

These may include, but are not limited to, criminal record checks or financial background checks where applicable.