Senior Site Reliability Engineer

Overview

Do you thrive on driving innovation through automation and DevOps principles? Can you architect and lead the delivery of secure, scalable platforms while mentoring others and influencing technical direction? Are you ready to shape the future of infrastructure in a mission-critical environment focused on National Security & Defence?

As a Senior Engineer, you will play a pivotal role in leading the design, development, and deployment of resilient, secure, and automated infrastructure solutions. You'll work closely with cross-functional teams, guiding technical strategy, mentoring engineers, and ensuring best practices across the platform lifecycle. Your work will directly impact the reliability, scalability, and security of both internal and customer-facing environments.

Key Responsibilities

• Technical Leadership: Lead the design and delivery of platform solutions, setting technical direction and ensuring alignment with strategic goals.
• Architecture & Design: Own the architecture of core services and platforms, driving innovation through automation, security, and performance optimization.
• Mentorship & Collaboration: Support and mentor engineers across the team, fostering a culture of continuous improvement and technical excellence.
• DevOps Advocacy: Champion DevOps principles and practices, embedding automation and reliability into every stage of the delivery lifecycle.
• Secure by Design: Embed security into infrastructure design and implementation, conducting risk assessments and ensuring compliance with best practices.
• Innovation & PoC Delivery: Evaluate emerging technologies, lead proof-of-concept initiatives, and transition successful solutions into production.
• Operational Excellence: Ensure robust monitoring, alerting, and documentation are in place to support high availability and rapid incident response.
• Stakeholder Engagement: Collaborate with project managers, support teams, and customers to deliver solutions that meet functional and non-functional requirements.

Essential Skills & Experience

• Deep expertise in Linux (Ubuntu, RHEL, CentOS) and Windows Server (2019/2022) administration.
• Strong proficiency in scripting languages (e.g., Bash, Python, PowerShell).
• Advanced experience with DevOps and automation tools (e.g., Ansible, Terraform, CI/CD pipelines, Git).
• Proven track record with cloud platforms (Azure, Azure Stack Hub, or similar).
• Experience designing and implementing Infrastructure as Code (IaC) and Configuration as Code solutions.
• Strong understanding of security best practices, including vulnerability assessments and system hardening.
• Excellent problem-solving, analytical, and communication skills.
• Ability to lead multiple projects in a fast-paced, agile environment.

Desirable Skills

• Experience with containerization and orchestration (Docker, Kubernetes, Podman).
• Familiarity with monitoring and alerting tools (Nagios, Splunk).
• Knowledge of COTS installation and automation.
• Hands-on experience with GitLab, JIRA, Confluence or similar tooling.
• Strong documentation and diagramming skills to communicate complex designs clearly.
• Ability to influence and drive change across teams and stakeholders.
• Must be willing to Travel worldwide, be eligible for Security Clearance (SC), and willing to apply for DV. Knowledge of Military exercises is desirable.

About SIXWORKS?

SiXworks is a leading provider of secure digital solutions, specialising in digital experimentation and focused on fail-safe-fast cutting-edge technology solutions deployed in highly secure environments. We accelerate innovation and adoption of secure, digital technology to improve the operational agility of Defence and National Security. We are growing and seeking brilliant, experienced, motivated, and passionate people to join our team.

Why join SiXworks?

Our team blends senior operational, technical, and business leadership from various industries and the armed forces. We are powered by IT engineers, architects, developers, and project managers collaborating to drive digital innovation.

SiXworks' expertise includes Secure-by-Design, cloud computing, advanced network and infrastructure design, rapid application development, cross-security domain systems, multi-tenanted High-Performance Compute, multi-source data platforms, cyber vulnerability mitigation, and intelligence systems. We provide supplier-agnostic technical and business consultancy to customers while championing open-source and best-of-breed technologies.

What can we offer in return?

SiXworks offers a unique work culture around six core principles: Agility, Security, Innovation, Quality, Collaboration and Inclusivity. These principles guide the organisation towards success and are reflected in the benefits available to all employees:

• 25 days annual leave + bank holidays.
• Private Medical Insurance.
• Life Assurance Scheme.
• Contributory pension scheme.
• Professional Development opportunities.
• Cycle to Work scheme.
• Perks at Work scheme.
• Discretionary Bonus scheme.
• Secure on-site parking, cafe, restaurant, and gym facilities.
• Casual dress.
• Free hot and cold drinks in our own kitchen/break-out.

A word on UK Security Clearance

Due to the secure nature of the position and working environment, you must have, or be eligible to obtain Security Clearance including DV. More details relating to UK Security Clearance can be found here: