Senior Site Reliability Engineer

Hornetsecurity’s Service Reliability (SR) team operates the infrastructure behind our email security and cybersecurity services. We process more than 200 million analyzed emails and scan over 100 million websites every day. Our infrastructure includes more than 4,000 servers, over 300 Kubernetes nodes and several hundred petabytes of data, in a 24/7 environment serving customers worldwide.

Following Vade’s integration into Hornetsecurity and Hornetsecurity’s acquisition by Proofpoint, our product and platform landscape continues to evolve. The SR team owns platform engineering across systems, networking and database services. Some mature, business-critical services need to be maintained, consolidated and modernized; other capabilities are still being designed and built.

As a Senior SRE, you will design, build, deliver and operate tailored platforms, primarily for internal product teams. You will take them from requirements and architecture through automation, deployment, production operations and ongoing improvement. Quality of Service guides our decisions: we aim to make services more reliable, maintainable and useful to customers.

Your Job

Product & Platform Ownership

• Own the technical lifecycle of platforms for one or more internal product teams, from requirements discovery and architecture to production operation and evolution.
• Turn product needs into platform designs, defining capacity, availability, performance, dependencies and operational requirements.
• Lead technical design discussions and reviews. Make trade-offs clear, challenge assumptions constructively and help teams address reliability and scaling risks.
• Share proven patterns and production learnings across teams, and help engineers apply them to their services.
• Work across Linux, Kubernetes, networking and database services as part of the SR team’s shared engineering scope.

Automation & Platform Delivery

• Automate Linux configuration and infrastructure operations using Puppet and scripting.
• Build and maintain delivery workflows with GitLab CI/CD. Use Argo CD to deploy and reconcile Kubernetes workloads through GitOps.
• Use Terraform where appropriate to provision and evolve infrastructure.
• Improve platform delivery with reusable automation, safe rollout and rollback procedures, and clear operational runbooks.
• Use Jira to coordinate project work, tickets and changes with internal customers. Work with issue types such as user stories, tasks and change requests, as well as workflows, filters and automation. Use Confluence for architecture and operational documentation.

Reliability & Performance

• Define user-relevant SLIs and SLOs with product teams, assess service performance against them and turn reliability gaps into engineering work.
• Review production readiness, including capacity, dependencies, failure modes, recovery procedures, monitoring, alerting and rollback plans.
• Participate in the production on-call rotation, coordinate incident response, lead root-cause analysis and follow corrective actions through to completion.
• Identify scaling and reliability risks early, and validate architectural changes against expected traffic, failure scenarios and recovery objectives.

Observability & Monitoring

• Define how each platform exposes service health through actionable metrics, logs and traces.
• Build dashboards and alerts around user impact and service objectives, reducing noisy alerts and improving time to detection.
• Work with developers to instrument services and use production evidence to guide diagnosis and reliability improvements.
• Use the monitoring and logging tools suited to each environment, including Icinga in selected contexts and the Elastic Stack where applicable.

Your Profile

You have 5 to 10 years of experience in Linux administration and infrastructure engineering. You have taken technical ownership beyond day-to-day operations and can move between system-level diagnosis, platform architecture and product discussions. You can explain your decisions and use operational evidence to improve them.

You communicate clearly in French and English. You bring a fresh perspective, question established approaches constructively and propose practical improvements while protecting service quality.

Strong Linux expertise is essential. Additional experience in these areas is an asset:

• Infrastructure and platforms: virtualization, private cloud infrastructure, Kubernetes, GitLab CI/CD, Argo CD / GitOps, and some experience with Terraform.
• Observability and reliability: monitoring, Icinga in selected environments, ELK / Elastic Stack, backup and business continuity.
• Automation: Puppet, Ansible, scripting and automation workflows.
• Jira and Confluence, or equivalent project and collaboration tools. Experience with project management, ticketing, change workflows, issue types, filters and automation is useful.
• Interest in AI-assisted engineering. Familiarity with several models, agent-based workflows or reusable agent skills is welcome; curiosity and practical judgement matter.

We will provide training on our internal tools and the group’s specific processes.

Your Benefits

• Executive status
• Fixed-hours arrangement
• 5 weeks of statutory paid vacation + RTT
• €10 meal vouchers, with €5.92 covered by Hornetsecurity
• 100% coverage of public transportation costs
• Health and life insurance coverage (Axa)
• Subsidized sports and wellness programs
• Access to an inter-company daycare
• International exchange program

Join us at a pivotal point in our growth, work in a close-knit team, and develop in an international and multicultural company.