System Administrator – Linux & Cloud Infrastructure

Free-Work UK; Reading; On-site; GBP 45,000 - 65,000; Full time

Job summary

CGI is seeking a System Administrator for the BOREALIS team in Reading. You will monitor secure cloud infrastructure, perform first-line support, and ensure availability and reliability of critical systems in a highly secure environment. Office-based, five days a week on site.

Role involves on-call duties, alert investigation, and collaboration with CGI colleagues to improve service performance and resolve issues promptly.

Qualifications

• Linux: Practical experience administering, supporting or troubleshooting Linux environments.
• Monitoring: Ability to interpret system metrics, logs and infrastructure health information.
• Troubleshooting: Proven ability to gather diagnostic information, investigate issues and determine appropriate next steps.
• Customer Support: Strong customer service and communication skills within a technical support environment.
• On-Call: Willingness and ability to participate in a 24x7 on-call rota.

Responsibilities

• Monitor & Maintain: Conduct daily system and infrastructure health checks, monitoring availability and performance.
• Investigate & Resolve: Identify alerts and incidents, perform initial troubleshooting and resolve first-line issues.
• Analyse & Improve: Use Grafana, Kibana, dashboards, logs and system metrics to identify potential problems and support continuous improvement.
• Diagnose & Escalate: Gather complete diagnostic information, error details and system context before escalating complex issues to technical teams.
• Support & Collaborate: Deliver responsive customer support while working closely with technical colleagues to restore services efficiently.
• Respond & Protect: Participate in the 24x7 on-call rota and respond to critical incidents when required.

Skills

Linux

Monitoring

Troubleshooting

Customer Support

On-Call

Agile

Security Awareness

Tools

Grafana

Kibana

Job description

The Space, Defence and Intelligence business unit in CGI is a true IT Systems Integrator. We work, build, and operate bespoke, technically complex, mission-critical systems which help our clients keep us all safe and secure. We bring innovation to our clients using proven and emerging technologies, agile delivery processes and our deep expertise across the breadth of space, defence, intelligence, aerospace and maritime, all underpinned by our end-to-end cyber capability. We work collaboratively with global technology companies, cutting edge SMEs and academia to deliver the optimal solution for each client.

CGI was recognised in the Sunday Times Best Places to Work List 2025 and has been named a UK ‘Best Employer’ by the Financial Times. We offer a competitive salary, excellent pension, private healthcare, plus a share scheme (3.5% + 3.5% matching) which makes you a CGI Partner not just an employee. We are committed to inclusivity, building a genuinely diverse community of tech talent and inspiring everyone to pursue careers in our sector, including our Armed Forces, and are proud to hold a Gold Award in recognition of our support of the Armed Forces Corporate Covenant. Join us and you’ll be part of an open, friendly community of experts. We’ll train and support you in taking your career wherever you want it to go.

CGI are on the lookout for a System Administrator to join our BOREALIS team and help keep secure, business-critical cloud infrastructure performing reliably for our clients. Based on site in Reading, you’ll play an important role in monitoring system health, identifying potential issues and providing responsive first-line support within a highly secure environment. You’ll have the autonomy to investigate alerts, use monitoring insights to solve problems and contribute to service improvements, while collaborating with experienced technical teams when more complex challenges arise. It’s an opportunity to build your expertise across Linux and cloud infrastructure, contribute ideas that strengthen service performance, and develop your career within a supportive CGI community where your contribution has a visible impact.

Due to the secure nature of the programme, you will need to be a sole UK National and hold UK Security Clearance or be eligible to go through this clearance. This is an office-based position, requiring 5 days per week onsite at our Reading location, and participation in a 24/7 on call rota.

Candidate Profile

In this role, you will take ownership of the day-to-day monitoring and first-line support of secure cloud infrastructure, helping maintain the availability, performance and reliability of critical systems. You’ll carry out daily health checks, proactively investigate alerts and use tools such as Grafana and Kibana to analyse dashboards, logs and system metrics.

You’ll apply your problem-solving skills to troubleshoot incidents, resolving issues where possible and gathering the technical information needed for efficient escalation when additional expertise is required. Working alongside CGI colleagues and technical teams, you’ll have opportunities to share ideas, improve ways of working and expand your knowledge. You’ll also participate in a 24x7 on-call rota, responding to critical incidents outside standard working hours when required.

• Monitor & Maintain: Conduct daily system and infrastructure health checks, monitoring availability and performance.
• Investigate & Resolve: Identify alerts and incidents, perform initial troubleshooting and resolve first-line issues.
• Analyse & Improve: Use Grafana, Kibana, dashboards, logs and system metrics to identify potential problems and support continuous improvement.
• Diagnose & Escalate: Gather complete diagnostic information, error details and system context before escalating complex issues to technical teams.
• Support & Collaborate: Deliver responsive customer support while working closely with technical colleagues to restore services efficiently.
• Respond & Protect: Participate in the 24x7 on-call rota and respond to critical incidents when required.

Required Qualifications To Be Successful In This Role

You’ll bring practical systems administration or previous cloud infrastructure support experience, with a strong grounding in Linux and confidence using monitoring and observability tools. You should be comfortable investigating technical issues methodically, interpreting system information and working collaboratively to deliver a reliable service. You’ll be supported by experienced colleagues while having the scope to take ownership of issues and develop creative solutions.

Essential

• Linux: Practical experience administering, supporting or troubleshooting Linux environments.
• Grafana: Experience using Grafana to review or create dashboards and analyse system performance.
• Kibana: Experience using Kibana to investigate logs, alerts and operational issues.
• Monitoring: Ability to interpret system metrics, logs and infrastructure health information.
• Troubleshooting: Proven ability to gather diagnostic information, investigate issues and determine appropriate next steps.
• Customer Support: Strong customer service and communication skills within a technical support environment.
• On-Call Support: Willingness and ability to participate in a 24x7 on-call rota.

Desirable

• Agile: Experience working within an Agile environment would be advantageous.
• Previous experience working within the space and defence sector