Job Summary: We are seeking a Senior Systems Administration Specialist to ensure high availability of JBoss applications, system security, and efficient resource management in hybrid environments (Linux and Windows). Key Highlights: 1. Solid experience in hybrid environments (Linux and Windows) 2. Responsible for high availability of JBoss applications and security 3. Efficient management of computing and network resources Senior Infrastructure Administrator We are seeking a Systems Administration Specialist with solid experience in hybrid environments (Linux and Windows). The ideal candidate will be responsible for ensuring high availability of our JBoss-based applications, system security through hardening, and efficient management of computing and network resources. Technical Responsibilities (Hard Skills) 1. Linux Specialist (RHEL, Suse, Oracle Linux) Resource Management: Monitoring and optimization of CPU, RAM, and Swap. Advanced storage management with LVM (disk extension and mounting). Security and Hardening: Implementation of security policies (CIS Benchmarks), vulnerability patching, and advanced SSH configuration (key-based authentication, root access restriction). Identity: Configuration and integration of Linux servers into Active Directory domain using SSSD or Realmd. Maintenance: Execution of Operating System upgrades and application deployments. Cloud Infrastructure: Management of OCI / Azure infrastructure. 2. Middleware (JBoss / WildFly) Configuration of instances (Standalone/Domain mode). Tuning of JVM parameters (Heap Memory, Garbage Collector). Log analysis and resolution of deployment errors (Troubleshooting). Configuration of interfaces and datasources. 3. Windows Server Administration Management of roles and features (AD, DNS, DHCP, File Server). Administration of users and groups in Active Directory. Management of Group Policies (GPO) for security and configuration. Monitoring of system events (Event Viewer) and performance. 4. Networking and Connectivity Diagnosis of connectivity issues (Layers 2 and 3). Use of network tools: tcpdump, netstat, telnet, nmap. Configuration of local firewalls (firewalld, iptables, Windows Firewall). Desirable Requirements Experience in automation (PowerShell and Bash scripting). Knowledge of monitoring tools (Zabbix, Nagios or similar). Ability to respond to critical incidents (On-call support). Competencies (Soft Skills) Analytical Thinking: Ability to identify root causes of complex infrastructure issues. Autonomy: Ability to perform maintenance and upgrade tasks with minimal supervision. Clear Communication: Ability to document processes and execution guides.-Requirements- Minimum education: Technical 5 years of experience Knowledge: Applications, Infrastructure, JBoss, Linux, Operating Systems, Windows, Server Administration, Systems Administration Keywords: administrator, senior, sr