The Linux System Administrator is responsible for ensuring the reliability, performance, and security of Linux-based systems and related infrastructure components. The role includes providing level 2-3 support, handling complex incident resolution, maintaining documentation, and participating in project and service design initiatives. The ideal candidate has extensive experience supporting large-scale Unix/Linux environments, strong automation skills, and the ability to work cross-functionally on infrastructure, networking, security, and application hosting topics. Your responsabilities Operational support & troubleshooting: Provide Level 2-3 support for Linux OS configuration, file systems, processes, log analysis, and system troubleshooting. Diagnose and resolve issues related to hosted applications, platforms, reverse proxies, and server environments (Intranet/Internet). Ensure proper execution of backup, Storage, and security-related operational tasks. System Administration & Infrastructure Management: Manage provisioning of Linux servers and VMS (including RHEL 8/9). Maintain a reliable, standardized, and compliant operating environment. Perform patch management, OS lifecycle operations, and migration activities. Administer and support the OpenShift container platform. Use GitLab for Version Control and CI/CD pipeline integration. Participate in high availability (HA) and disaster recovery (DR) design and implementation. Administer and support Red Hat Satellite and manage Satellite-based environments. Administer and support Reverse Proxy platforms for on-premises and Cloud (AWS) Automation scripting: Develop and maintain automation using Red Hat Ansible Platform to improve reliability, repeatability, and operational efficiency. Contribute to service design with a focus on automation and "shift-left" practices Documentation & process: Maintain accurate and up-to-date technical documentation and operational procedures. Ensure compliance with ITIL processes (incident, change, problem management). Perform activity reporting and manage operational priorities. Organize knowledge-sharing workshops within the team. ServiceNow for ticketing and workflow management. Linux platforms & services: Proxies (Squid), reverse proxies (NGINX), and nftables Firewalls configuration. Manage SSL/TLS certificates and Linux security configurations. Java- and Spring Boot-based webservers and Artemis MQ. Handle client/agent support such as metricbeat, filebeats, and NetBackup. Data transfer Moveit administration, rsync Datacenters infrastructure and Cloud: Support authentication systems including SAML/OIDC, ADFS, and Azure Entra ID. Networking IPv4, Virtualization (Nutanix), databases (Oracle, PostgreSQL), and Storage (SAN, NAS, S3). Containerisation: Kubernetes, Docker, and Podman. Qualifications Experience: Minimum 8 years of proven hands-on experience managing Unix/Linux systems, ideally within a large-scale or critical production environment. Education / Certifications (optional section, add if desired) Degree in Computer Science, Information Technology, or equivalent experience. Relevant certifications (RHCSA, RHCE, Kubernetes, Ansible, ITIL, etc.) are a plus. Key competencies: Strong expertise with Red Hat Enterprise Linux (RHEL) 8/9. Experience with Java/NGINX application servers. Additional knowledge: Nutanix Virtualization Oracle, PostgreSQL Kubernetes / OpenShift / Docker / Podman NGINX reverse proxy GitLab and CI/CD pipelines PAM/SAM solutions Backup & Storage solutions (SAN, NAS, S3) Advanced network knowledge (IPv4, DNS, Firewall, Routing, DMZ) ELK Stack Java/SpringBoot hosting architectures Messaging systems such as Artemis MQ Why cronos group? We'll propose you: An attractive salary package A good work-life balance environment The assurance of working in cutting-edge technologies in an entrepreneurial spirit. The opportunity to develop your skills thanks to tailor-made training courses according to your needs A good job in a friendly place If you wish to integrate a dynamic structure on a human scale while working with the latest technologies, don't wait anymore and join Cronos! Cronos Europa is an IT and digital communications company uniquely dedicated to serving the European institutions, agencies and bodies. From the European Union to EUROCONTROL, we partner with a range of supranational and interinstitutional authorities. Our mission is to arm them with the tools they need to thrive in the digital age. Every aspect of our organisation is designed to complement their capabilities - from our people to our processes and our premises. Our brand combines the expertise of former companies Cronos International and C-Dev, with the creative skills of Inspiiro and the breadth of capabilities of the Cronos Group. Today, Cronos Europa employs over 1,000 people in offices across Belgium, Luxembourg and the Netherlands, serving institutions across diverse framework contracts. Cronos Europa is part of the Cronos Group, one of the largest IT service providers in the Benelux, employing over 8,000 people across 200 competence centres. By leveraging the Group's resources, Cronos Europa can help clients extract value from new and emerging technologies, for everything from Artificial intelligence to Zg Quantum.