Senior Systems Engineer

If you're an experienced Unix/Linux engineer who thrives on variety – BAU, projects, problem-solving, and new tech – this is a brilliant opportunity to join a team where no two days look the same. You'll provide advanced 3rd (and sometimes 4th) line expertise across on‐prem, hybrid and public cloud Unix/Linux platforms, supporting a multi‐client estate and helping keep critical services running smoothly.

What we're looking for

• Strong Unix/Linux engineering capability, plus the confidence to operate at senior escalation level.
• Proven experience in a 3rd Line Support / Infrastructure Engineer (or similar senior technical) role supporting large, enterprise environments.
• Strong recent experience managing Unix/Linux server platforms in production.
• In‐depth admin knowledge across multiple OSs such as RHEL (v7+), Oracle Linux (v7+), SUSE (v15+), Ubuntu (v18+), AIX (v7.2+); including System P virtualisation (LPARs), PowerHA/SystemMirror/Cluster Aware AIX/HACMP & Solaris (10/11) (including Perl scripting).
• Experience supporting environments with Oracle RAC.
• Experience working across public cloud platforms such as Azure, AWS, PowerVS, Oracle Cloud.
• Strong troubleshooting and analytical skills with the ability to provide clear, actionable solutions.
• Confident communication – able to explain complex issues to technical and non‐technical stakeholders, including senior audiences.

This position requires Security Clearance (SC) eligibility, and candidates must be UK‐based.

What you'll be doing

• Take end‐to‐end ownership across the platform lifecycle, from building and optimising environments to leading on complex incidents and improvements.
• Lead the administration, configuration and support of Linux and Unix environments (e.g., RedHat, SUSE, AIX, Solaris) in line with operational processes and policies.
• Act as the technical owner for priority and complex incidents, providing deep troubleshooting, resolution and clear stakeholder updates throughout.
• Work across BAU and project delivery, contributing to upgrades, migrations, and infrastructure improvements.
• Build and support servers across a range of environments, including cloud and platform‐specific Unix estates.
• Drive root cause analysis for recurring issues and implement long‐term corrective actions.
• Assess and execute change in line with ITIL‐aligned service management.
• Support enterprise toolsets and services that run across Unix/Linux environments.
• Collaborate with internal teams and third parties/suppliers to deliver effective outcomes.
• Author and maintain high‐quality documentation (procedures, diagrams, KB articles).
• Support DR planning and testing and ensure security/compliance best practices are met.

Please note that this role participates in an out‐of‐hours on‐call rotation (currently 1 in 4). Coverage is 6 pm‐8 am Monday‐Friday, plus the full weekend.

Benefits

• Home‐based working.
• 23 days' holiday (rising to 27) with the opportunity to buy extra leave.
• Company matched pension, life assurance, 15 weeks' fully paid maternity, adoption and shared parental leave, paternity pay of two weeks and plenty more.
• Volunteering for our charity partners or a cause of your choice – opportunity to take a paid day out of the office.
• Access to our Employee Network Groups, which represent every strand of diversity and allow colleagues to connect and learn from each other on an open, inclusive platform.
• Opportunity to gain additional qualifications through our Learning Academy or apprenticeships to help develop your career.

Equal Opportunity

We're an equal opportunity and Disability‐Confident employer, which means we recruit and develop people based on their merit and passion. We're committed to providing an inclusive, barrier‐free recruitment process and working environment for everyone. If you need the job description or application form in an alternative format (such as large print or audio), or if you'd like to discuss other changes or support you might need going forward, please email reasonableadjustments@capita.com and we'll get back to you. For more information about equal opportunities and process adjustments, please visit the Capita Careers website.