Specialist, Linux Administration

Colt Technology Services Group Ltd.; Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Benefits offered by this job

Flexible working hours

Work from home option

Mentors and buddies

Development opportunities

Global Family Leave Policy

Employee Assistance Program

Diversity networks

Job summary

Colt Technology Services Group Ltd. is seeking a Senior Linux Administrator to own and optimize the Linux infrastructure underpinning critical business apps.

You will join a team supporting thousands of Linux systems, driving automation, security, resilience, and continuous improvement. The role requires deep technical expertise, strong troubleshooting, and collaboration with architecture, security, and operations teams across the organisation.

Qualifications

• 8+ years of Linux administration experience in enterprise environments.
• Experience with cloud platforms (AWS, Azure, GCP).
• Familiarity with containerization (Docker, Kubernetes).
• RHCE, LFCS, LFCE or security-related certifications are a plus.

Responsibilities

• Serve as a senior technical expert for Linux systems and provide advanced engineering support.
• Define and implement roadmaps for Linux infrastructure and services.
• Develop and maintain operating procedures for secure, stable system management.
• Design solutions for security, resilience and high availability.
• Drive automation using Ansible and other tools to reduce manual effort.
• Lead complex Linux troubleshooting and ensure patching and hardening aligned to standards.
• Collaborate with security/compliance teams and support identity management (LDAP).
• Document engineering solutions and support audits.

Skills

Linux administration

Cloud platforms (AWS, Azure, GCP)

Docker/Kubernetes

Troubleshooting

Security & compliance knowledge

Education

Bachelor’s degree in Computer Science or related field

Tools

Docker

Kubernetes

Job description

Colt provides network, voice and data centre services to thousands of businesses around the world, allowing them to focus on delivering their business goals instead of the underlying infrastructure.

Why we need this role

We are seeking a highly skilled Senior Linux Administrator who will act as a technical subject matter expert within the Linux Engineering team. The role is accountable for designing, implementing, supporting, and optimising the Linux infrastructure that underpins critical business applications.

The successful candidate will work as part of a team supporting approximately 4000 Linux systems, contributing to technology roadmaps, automation initiatives, operational excellence, and continuous improvement. This role requires deep technical expertise, strong troubleshooting skills, and the ability to collaborate effectively with architecture, security, and operations teams across the organisation.

What you will do

• Serve as a senior technical expert for Linux systems, providing advanced engineering support and guidance.
• Contribute to the definition and implementation of technology roadmaps for Linux infrastructure and associated services.
• Develop and maintain operating procedures to ensure secure, stable, and efficient system management.
• Design and implement solutions that meet security, compliance, resilience, and high availability requirements.
• Drive automation using Ansible and other tools to streamline operational tasks and reduce manual effort.
• Lead complex troubleshooting activities across Linux platforms and integrated technologies.
• Support patching, hardening, and configuration management activities aligned to security and compliance standards.
• Work closely with security and compliance teams to ensure adherence to regulatory frameworks and internal controls.
• Support and enhance DNS and identity management solutions, including Red Hat and Oracle LDAP.
• Develop and maintain documentation for engineering solutions, operational processes, and compliance audits.
• Participate in the Infrastructure Operations on call rota to provide out of hours support for priority incidents

What we’re looking for

• Supporting the Infrastructure Team to design, implement and maintain IT infrastructure components, including servers, networks, storage systems, and cloud resources.
• Troubleshooting and resolving technical issues related to infrastructure components to ensure uninterrupted operations.
• Monitoring and optimizing the performance, security, and availability of IT infrastructure.
• Providing subject matter expertise to develop and execute infrastructure projects and strategies.
• Supporting disaster recovery and business continuity planning and testing.
• Contributing to the assessment and selection of vendors for hardware, software, and service provision.

Qualification

• Bachelor’s degree in Computer Science, Information Technology, or related field (or equivalent experience).
• 8+ years of Linux administration experience, ideally within a large scale or enterprise environment.
• Experience with cloud platforms (AWS, Azure, GCP).
• Familiarity with containerization (Docker, Kubernetes).
• Certifications such as RHCE, LFCS, LFCE, or security related credentials.

What we offer you:

At Colt, you’ll make a difference. Because around here, we empower people. We don’t tell you what to do.

Instead, we employ people we trust, who come together across the globe to create intelligent solutions.

Our global teams are full of ambitious, driven people, all working together towards one shared purpose: to put the power of the digital universe in the hands of our customers wherever, whenever and however they want.

We give our people the opportunity to inspire and lead teams, and work on projects that connect people, cities, businesses, and ideas. We want you to help us change the world, for the better.

Diversity and inclusion

• Inclusion and valuing diversity of thought and experience are at the heart of our culture here at Colt. From day one, you’ll be encouraged to be yourself because we believe that’s what helps our people to thrive. We welcome people with diverse backgrounds and experiences, regardless of their gender identity or expression, sexual orientation, race, religion, disability, neurodiversity, age, marital status, pregnancy status, or place of birth.

Most recently we have:

• Signed the UN Women Empowerment Principles which guide our Gender Action Plan
• Trained 60 (and growing) Colties to be Mental Health First Aiders
• Please speak with a member of our recruitment team if you require adjustments to our recruitment process to support you. For more information about our Inclusion and Diversity agenda, visit our DEI pages.

Our benefits support you through all parts of life, for both physical and mental health.

• Flexible working hours and the option to work from home.
• Extensive induction program with experienced mentors and buddies.
• Opportunities for further development and educational opportunities.
• Global Family Leave Policy.
• Employee Assistance Program.
• Internal inclusion & diversity employee networks.

A global network

• When you join Colt you become part of our global network. We are proud of our colleagues and the stories and experience they bring – take a look at ‘Our People’ site including our Empowered Women in Tech.