Overview
We are seeking an experienced IT Systems Administrator to manage, maintain, and secure our enterprise IT infrastructure. The role involves supporting a full-stack environment, spanning Windows and Linux systems, utilising (not limited to) SANs (multipath I/O), clustered and virtualised servers, high-availability firewalling, replicated storage systems, application servers, mail systems, backup solutions, and VoIP systems. The successful candidate will play a key role in ensuring N+ redundancy, clustering, and high availability across all critical systems, safeguarding service delivery of our bespoke SaaS platform for customers.
Responsibilities
Infrastructure Management
* Administer and maintain Windows and Linux servers across production and development environments.
* Manage SAN storage, ensuring correct multipath I/O configuration, performance tuning, and redundancy.
* Deploy, monitor, and maintain virtualisation environments for high availability.
* Ensure N+1 redundancy across compute, storage, and network layers to minimise single points of failure.
* Implement and maintain server clustering for critical services (databases, applications, file servers, etc.).
Network & Security
* Configure and maintain VLANs, firewalls, VPNs, and routing for secure and segmented traffic flows.
* Deploy and maintain high availability (HA) firewalls in active/passive configurations to guarantee continuous protection and uptime.
* Monitor and harden network services to prevent intrusion and ensure compliance with best practices.
* Conduct vulnerability assessments, patching, and incident response for infrastructure security.
SaaS Application Server Management
* Administer and maintain the application servers powering our bespoke SaaS platform, ensuring high performance, scalability, and reliability.
* Implement monitoring, alerting, and proactive maintenance strategies to support 100% planned uptime for customer-facing services.
* Manage load balancing, clustering, and redundancy across application tiers to maintain continuous availability during updates, failovers, or infrastructure events.
* Collaborate with development teams to roll out new releases, patches, and configuration changes in a controlled and resilient manner.
* Optimise resource usage and capacity planning to support business growth and customer demands without impacting service quality.
* Conduct regular performance testing, tuning, and root cause analysis of application-level incidents.
* Maintain strong security practices across SaaS infrastructure, ensuring customer data integrity and regulatory compliance.
* Administer and maintain VoIP telephony systems with redundancy and failover support.
* Manage and support secure remote worker access with VPN and endpoint management solutions.
* Maintain and secure mail systems and instant messaging, including clustered configurations for uptime, spam/phishing protection, and compliance.
Data Protection & Continuity
* Oversee enterprise backup and disaster recovery solutions.
* Configure replicated and redundant backup strategies across multiple storage sites.
* Regularly test failover scenarios, including SAN multipath I/O, clustered servers, and HA firewalls.
* Develop and enforce business continuity plans aligned with enterprise recovery time objectives (RTOs) and recovery point objectives (RPOs).
Operational Support
* Provide advanced troubleshooting and escalation support for IT incidents and outages.
* Document infrastructure, HA topologies, and operational procedures.
* Work closely with development and SaaS delivery teams to align IT systems with customer-facing SLAs.
Required Skills & Experience
* Systems Administration
* Strong experience with Linux (RHEL/Ubuntu) and Windows Server administration.
* Proven experience with clustered and high-availability server deployments.
* Hands-on experience with SANs and multipath I/O.
* Virtualisation expertise with libvirtd/KVM, including HA and clustering.
* Networking & Security
* Strong knowledge of VLANs, routing, switching, and firewall management.
* Familiarity with load balancers, redundancy strategies, and fault-tolerant networking.
* Knowledge of IDS/IPS systems, SIEM, and enterprise security frameworks.
* Services & Applications
* Experience with clustered databases (e.g., MySQL, PostgreSQL and MS SQL clusters).
* Management of VoIP systems (Asterisk/FreePBX or equivalent) with redundancy.
* Experience running and securing mail systems.
* Familiarity with DNS, DHCP, LDAP/Active Directory, and identity federation.
* Backup & Disaster Recovery
* Strong background in enterprise backup technologies.
* Experience with redundant and offsite backups.
* Disaster recovery testing and HA failover experience.
* General Skills
* Proficiency in automation and scripting (Bash, PowerShell, Python, Ansible).
* Excellent problem-solving in complex, multi-layered enterprise environments.
* Strong communication and documentation skills.
* Ability to design, implement, and maintain redundant, fault-tolerant systems.
Preferred Qualifications
* Certifications: RHCE/RHCSA, MCSE, or equivalent.
* Experience in SaaS or high-availability hosting environments.
* Familiarity with compliance frameworks (ISO 27001, SOC 2, GDPR).
* Experience with enterprise monitoring/observability platforms.
What We Offer
* Hands-on exposure to enterprise-scale high-availability infrastructure.
* Professional development and certification opportunities.
* A collaborative culture focused on innovation, security, and resilience.
Seniority level
* Mid-Senior level
Employment type
* Full-time
Job function
* Information Technology
Industries
* IT Services and IT Consulting
#J-18808-Ljbffr