Principal Site Reliability Engineer in London

The Principal Site Reliability Engineer (SRE) is a senior technical leader responsible for shaping how reliability, automation, and operational excellence are engineered across the organisation. Operating across domains including traditional infrastructure, cloud engineering, network operations, identity, observability, security, AI-driven operations, and automated data workflows, the role focuses on designing scalable systems, reusable engineering patterns, and standardised controls that reduce operational toil, improve resilience, and embed reliability, governance, and compliance directly into delivery pipelines and operational platforms. This role will drive organisational change towards automation-first, measurable, and repeatable practices.

A key part of the role is building and evolving reusable CI/CD and Terraform modules, engineering guardrails, observability patterns, and automation frameworks that can be adopted across multiple teams and domains without requiring each team to solve the same problems independently. The Principal SRE also plays an important enablement role beyond deeply technical teams, helping less technical areas of the business adopt structured, governed, and scalable ways of working. This includes translating complex engineering practices into practical standards, improving how governance is implemented through engineering controls rather than manual oversight, and driving operational maturity across a broad and diverse technology landscape.

The ideal candidate is a systems thinker who understands how services, networks, identity, data flows, and operational processes fail in real-world conditions, and can apply that understanding to build automation-first, reliability-focused operating models that scale across both technical and non-technical functions.

• Cross-Domain Reliability Engineering
• Design and evolve reliability patterns across cloud, network, identity, and security domains.
• Identify systemic risks and failure modes across platforms and services, and define engineering solutions to mitigate them.
• Ensure operational activities are embedded into delivery models through automation, CI/CD integration, and event-driven workflows.
• Automation & Toil Reduction at Scale
• Lead the design of automation frameworks that eliminate manual operational tasks across multiple domains.
• Translate incident learnings and operational inefficiencies into scalable automation and preventative controls.
• Drive adoption of automation-first principles, reducing dependency on human-driven processes.
• Contribute to AI-driven operational use cases, including event correlation, anomaly detection, noise reduction, operational insights, and automated remediation.
• Ensure AIOps capabilities are grounded in reliable telemetry, clear control boundaries, and measurable operational outcomes.
• Observability & 24/7 Operational Excellence
• Define standards for telemetry, monitoring, alerting, and operational visibility across all critical systems.
• Ensure services are observable, measurable, and support proactive detection of issues.
• Improve operational readiness, incident response effectiveness, and time-to-recovery through engineering solutions.
• CI/CD & Platform Integration
• Contribute to the design of CI/CD patterns that embed reliability, security, and operational controls into pipelines.
• Ensure infrastructure, network, identity, and security configurations are managed through code and validated automatically.
• Support integration of platform services into delivery pipelines to enable consistent, repeatable deployments.
• Security & Identity Integration
• Contribute to secure-by-design patterns, including least privilege, identity-based access, and short-lived credentials.
• Support integration of security controls (e.g. secrets management, authentication, policy enforcement) into engineering workflows.
• Ensure security and compliance requirements are met through engineering controls rather than manual processes.
• Network & Infrastructure Reliability
• Support the design of resilient network architectures and segmentation aligned with Zero Trust principles.
• Ensure network configurations and controls are automated, validated, and observable.
• Contribute to infrastructure design patterns that improve availability, scalability, and fault tolerance.
• Design and improve operational patterns for network reliability, segmentation, visibility, and change validation.
• Support automation and standardisation of network controls and operational procedures to reduce manual intervention and configuration drift.
• Technical Leadership & Enablement
• Provide technical leadership across teams, influencing standards, architecture, and engineering practices.
• Mentor engineers on reliability engineering, automation, and systems thinking.
• Drive consistency through reusable patterns, frameworks, and documentation.
• Strategic Influence & Continuous Improvement
• Contribute to reliability engineering strategy and roadmap across the organisation.
• Communicate technical concepts, risks, and recommendations to senior stakeholders and leadership.
• Lead initiatives that improve reliability maturity, engineering efficiency, and operational scalability.
• Support less technical teams and functions in adopting structured, automated, and measurable operational practices.
• Act as a bridge between engineering capability and organisational change, helping scale good practice beyond core platform teams.
• Automated Data Workflows
• Design and improve automated data workflows that support operational reporting, observability, governance, and decision-making.
• Ensure operational data pipelines are reliable, timely, and aligned to engineering and business needs.
• Reusable Engineering Frameworks
• Build and evolve reusable modules, patterns, and frameworks for CI/CD, Terraform, and operational automation.
• Embed governance, validation, and reliability controls into these shared engineering assets by default.
• Governance by Engineering
• Translate governance requirements into practical engineering controls, automated checks, and repeatable standards.
• Help teams adopt compliant and supportable operating models without relying on manual policing or process-heavy interventions.

• 10+ years of experience in Site Reliability Engineering, Platform Engineering, or related fields.
• Strong hands-on experience across multiple domains, including:
• Cloud platforms (AWS, Azure)
• CI/CD and Infrastructure-as-Code (e.g. Terraform)
• Observability tools (e.g. Datadog, Splunk)
• Automation and scripting (e.g. Python)
• Experience designing and implementing scalable automation and reliability solutions.
• Deep understanding of distributed systems, failure modes, and resilience patterns.
• Experience integrating operational and security controls into engineering workflows.
• Strong stakeholder engagement and technical communication skills.

• Experience with identity and access management systems (e.g. Entra ID, Vault).
• Experience with network architecture and security controls (e.g. firewalls, segmentation).
• Familiarity with Zero Trust principles and security engineering practices.
• Experience working in large, federated organisations with diverse technology stacks.
• Exposure to compliance and regulatory requirements (e.g. PCI, HIPAA, SOX).

• Hybrid or on-site work model.
• Operates as a senior individual contributor with broad cross-organisational influence.
• Expected to balance hands-on technical leadership with strategic direction.
• Occasional travel may be required for team or stakeholder engagement.