Linux/Unix Administrator We are seeking a Systems Administrator to join our critical Air Traffic Management (ATM) operational environment. The selected candidate will work on-site at the Gavá Air Traffic Control Center, performing administration, maintenance, and support of UNIX/Linux-based systems, local networks, and x86 architectures within a mission-critical environment. This position requires a strong technical profile, quality-oriented, and capable of working in highly regulated and sensitive environments. Key Responsibilities Administer, maintain, and monitor UNIX/Linux-based systems (especially Red Hat). Manage and provide support for x86 architectures in critical environments. Administer and configure Cisco equipment and LAN communications. Collaborate in ATM system operations, support, and continuous improvement activities. Participate in incident resolution and technical analysis. Produce technical documentation, procedures, and operational reports. After acquiring the required knowledge level, participate in 24-hour on-call support shifts (rotating schedule: 50% of the time, one week on, one week off). Occasional domestic travel (up to 3 trips per year, 3 days each). Essential Technical Requirements Minimum 3 years’ experience administering UNIX/Linux systems. Solid knowledge of Red Hat. Experience with LAN communications and networking (routers, switches, protocols). Knowledge of Cisco equipment. Familiarity with x86 architectures. Degree in Telecommunications Engineering or Computer Science. Intermediate level of English. Additional Requirements Willingness to travel occasionally within Spain. Availability to perform on-call duties once the necessary know-how has been acquired. Ability to work in mission-critical environments where security and compliance are essential. Job Conditions **Work Mode:** 100% on-site at the Gavá Air Traffic Control Center. **PPE and Occupational Risk Prevention (PRL):** Primarily office-based role (risks associated with data display screens). On-call duties: After an adaptation period, 24-hour on-call shifts on a rotating weekly basis (50% of the time). Coordination with another team member. **We Offer:** Indefinite contract with CAS Training Opportunity to join a high-level European technical team in an innovative environment Attractive and flexible compensation package, negotiated according to your experience Free access to our Annual Training Catalog featuring top manufacturers: Microsoft, Linux, Oracle, ITIL, and many more! Linux, Unix, Shell scripting, Red Hat, x86, Cisco, LAN,