Site Reliability Engineer (Mid / Senior)

Site Reliability Engineer (Mid / Senior) South West London (Hybrid – 1–2 days onsite) Salary: Competitive + Benefits We are looking for a Site Reliability Engineer to join a well-established small infrastructure team supporting a highly available, production environment. This is an exciting opportunity to work across a modern, self-hosted platform spanning Kubernetes, physical infrastructure and automation, with a strong focus on Ubuntu-based systems. The Role As an SRE, you will play a key role in ensuring the availability, performance, security and resilience of production systems. Working in a small, collaborative team, you’ll take ownership of day-to-day platform operations, incident response and continuous improvement, while partnering closely with development teams to deliver reliable and scalable services. Key Responsibilities • Administer and maintain Linux (Ubuntu) server environments • Manage self-hosted Kubernetes clusters and supporting infrastructure • Support on-premise infrastructure including physical servers and virtualisation platforms • Administer storage solutions including NFS, iSCSI and object storage • Build and maintain automation using Ansible or similar IaC tools • Develop operational tooling using Bash and Python • Monitor system health using tools such as Prometheus, Grafana, Zabbix or Nagios • Investigate and resolve production incidents (on-call rota involved) • Implement security hardening and infrastructure best practices • Manage backup and disaster recovery processes and regular testing • Support and improve CI/CD pipelines and deployment processes • Collaborate with engineering teams to improve reliability and performance Essential Skills • Strong Linux systems administration (Ubuntu preferred) • Experience running production Kubernetes environments • Solid understanding of networking (TCP/IP, DNS, routing, firewalls) • Experience with physical servers and virtualisation platforms • Hands-on experience with Ansible or other IaC tools • Scripting skills in Bash and Python • Experience with monitoring and alerting platforms • Knowledge of Linux storage technologies (NFS, iSCSI) • Experience with backup & disaster recovery • Exposure to Active Directory / Entra ID / endpoint management • Strong troubleshooting and problem-solving skills Desirable Experience • Object storage, MariaDB or database administration • CI/CD tools such as Jenkins • AWS (S3, Lambda, CloudFront) exposure • Terraform or additional IaC tooling • Experience with Harvester or similar platforms • Knowledge of security, compliance or GDPR Why Apply? • Work on complex, real-world infrastructure (not just cloud-native) • High ownership in a small, collaborative team • Exposure to a broad modern tech stack across infra, Kubernetes and automation • Hybrid working with a competitive salary package