Linux Infrastructure Engineer

ByDesign Secure Systems Ltd; City Of London; Hybrid; GBP 65,000 - 90,000; Full time

Job summary

ByDesign Secure Systems Ltd in London is seeking an experienced Infrastructure Engineer to design, build, and support secure, scalable Linux infrastructure for air-gapped government systems. You will administer IdM, Keycloak, BIND, Guacamole, and patch and harden RHEL systems while aligning with enterprise standards.

The role requires hands-on expertise in Ansible, Terraform, and IaC, with experience in regulated environments and limited connectivity.

Qualifications

• Proven hands-on experience as an Infrastructure or Linux Engineer in enterprise environments.
• Hands-on knowledge of Red Hat IdM, Keycloak, BIND DNS and Guacamole.
• Practical hands-on knowledge of IaC automation (Ansible) and strong experience with GitLab.
• Experience working in environments without direct internet connectivity.
• Confident working within highly regulated or classified environments where reliability and compliance are paramount.
• Strong communicator — able to bridge technical and Non-Technical stakeholders effectively.
• Good standard of written communication to enable high quality design outputs to be produced.

Responsibilities

• Design, build, and support secure, scalable, and highly available Linux infrastructure services for critical air-gapped environments.
• Administer and maintain Red Hat IdM and Keycloak platforms, providing resilient identity, authentication, and access management services.
• Deploy, manage, and support Apache Guacamole and BIND DNS services, ensuring secure remote access and reliable enterprise name resolution.
• Operate and maintain solutions within disconnected, air-gapped, and security-sensitive environments, ensuring compliance with organisational security requirements.
• Collaborate with architecture, security, and engineering teams to deliver infrastructure solutions aligned with enterprise standards and best practices.
• Administer and optimise Red Hat Enterprise Linux (RHEL) systems, including patching, hardening, lifecycle management, and vulnerability remediation.
• Implement and maintain infrastructure automation and configuration management using tools such as Ansible, Terraform, and shell scripting.
• Monitor, troubleshoot, and resolve platform and service issues, providing second- and third-line support for business-critical systems.
• Develop and maintain technical documentation, including High-Level Designs (HLDs), Component-Level Designs (CLDs), Low-Level Designs (LLDs), operational procedures, and support runbooks.
• Produce and present technical designs, implementation plans, and service improvements through governance and Technical Design Authority (TDA) processes as required.

Skills

Linux

Red Hat IdM

Keycloak

BIND DNS

Guacamole

Ansible

Terraform

Shell scripting

GitLab

Air-gapped environments

Tools

GitLab

Terraform

Ansible

Shell scripting

Job description

Join the Mission

At ByDesign Secure, we believe that world-class security shouldn't be an afterthought—it should be the foundation. We are an independent, outputs-based consultancy dedicated to solving the most complex data assurance challenges in the UK public sector. Currently, we working on a landmark transformation of a cross-government secure IT system. This is an exciting opportunity to help architect a private cloud environment from the ground up and modernize the end-user services that power national decision-making. We don't believe in "billing by the hour" or rigid hierarchies; we are a lean, expert team focused on delivering high-impact technical outcomes. If you are a self-starter who thrives on autonomy and wants to see your engineering or architectural decisions shape the future of sovereign security, we want to talk to you.

About the Opportunity

Are you an Infrastructure Engineer with a passion for engineering secure, mission-critical systems?

We’re looking for an experienced Infrastructure Engineer with deep Linux skills to join our team. You’ll be part of a multi-year transformation programme, shaping and implementing some of the most strategically significant government systems in operation today.

What You’ll Be Doing

Design, build, and support secure, scalable, and highly available Linux infrastructure services for critical air-gapped environments.

Administer and maintain Red Hat Identity Management (IdM) and Keycloak platforms, providing resilient identity, authentication, and access management services.

Deploy, manage, and support Apache Guacamole and BIND DNS services, ensuring secure remote access and reliable enterprise name resolution.

Operate and maintain solutions within disconnected, air-gapped, and security-sensitive environments, ensuring compliance with organisational security requirements.

Collaborate with architecture, security, and engineering teams to deliver infrastructure solutions aligned with enterprise standards and best practices.

Administer and optimise Red Hat Enterprise Linux (RHEL) systems, including patching, hardening, lifecycle management, and vulnerability remediation.

Implement and maintain infrastructure automation and configuration management using tools such as Ansible, Terraform, and shell scripting.

Monitor, troubleshoot, and resolve platform and service issues, providing second- and third-line support for business-critical systems.

Develop and maintain technical documentation, including High-Level Designs (HLDs), Component-Level Designs (CLDs), Low-Level Designs (LLDs), operational procedures, and support runbooks.

Produce and present technical designs, implementation plans, and service improvements through governance and Technical Design Authority (TDA) processes as required.

What You’ll Bring

Proven hands-on experience as an Infrastructure or Linux Engineer operating in enterprise environments.

Practical hands-on knowledge of key systems including Redhat IdM, Keycloak, BIND DNS and/or Guacamole.

Practical hands-on knowledge of IaC automation (Ansible) and strong experience with Gitlab.

Experience working in environments without direct internet connectivity.

Confident working within highly regulated or classified environments where reliability and compliance are paramount.

Strong communicator — able to bridge technical and Non-Technical stakeholders effectively.

Good standard of written communication to enable high quality design outputs to be produced.

Bonus Points For

Strong experience working in GCP and/or with Kubernetes.

Expertise in networking, IAM, containerisation (GKE/Kubernetes), and secure systems design.

Prior experience working on government classified systems or within secure data centre environments.

Experience of configuring and using AI technologies within cloud environments, including GCP AI technologies.

Familiarity with NCSC guidance, UK Government cloud policies, or cross-domain architectures.

Knowledge of multi-cloud integrations, edge computing, and data sovereignty requirements.

Google Certifications.

Existing DV clearance.

Why This Role?

Work on high-impact, nationally significant projects that make a real difference.

Join a trusted specialist integrator with a proven record of secure delivery into UK Government.

Be part of a multi-year programme offering long-term stability and genuine career growth.

Clearance Requirements:

This role requires either an existing Security Clearance (SC level) or for one to be passed before commencement. There must be a willingness to undergo Developed Vetting (DV).

Work Location: Hybrid remote in London

Job Types: Temporary, Fixed term contract (outside of IR35)

Screener Questions:

1. Do you hold UK nationality? (Required due to client security restrictions)

2. Do you currently hold active UK SC clearance?

3. Are you eligible and willing to undergo UK SC/DV clearance for this role? (Applications without this cannot be considered)

4. Does your delivery approach allow for on-site presence in London when required (typically around 3 days per week)?