Linux & Middleware Administrator

Overview Vertex Computer Systems is seeking an experienced Linux & Middleware Administrator to support enterprise IT infrastructure and business-critical applications. The ideal candidate will have strong hands-on experience with Linux systems administration, middleware technologies, Java application support, and enterprise deployment environments. This role involves maintaining and troubleshooting Linux and middleware platforms while collaborating with Development, DevOps, Infrastructure, Network, Security, and Operations teams. The successful candidate will have strong technical troubleshooting skills and the ability to resolve complex issues across operating systems, middleware, applications, and network infrastructure. ## Responsibilities - Administer, maintain, patch, monitor, and troubleshoot Linux environments, particularly Red Hat Enterprise Linux (RHEL). - Install, configure, maintain, and troubleshoot Apache HTTP Server, NGINX, Docker, and Red Hat JBoss Enterprise Application Platform (EAP). - Manage JBoss configurations, application deployments, JVM settings, data sources, certificates, logging, and clustering. - Analyze system and application logs to identify performance, configuration, connectivity, and availability issues. - Support SSL/TLS certificates, keystores, truststores, and application connectivity. - Troubleshoot Java/Jakarta EE applications, including application logs, stack traces, JVM errors, and configuration files. - Collaborate with development teams to resolve application, middleware, and infrastructure-related issues. - Support application builds and deployments across development, testing, and production environments. - Troubleshoot deployment failures, dependency issues, permissions, and environment configuration differences. - Support Git-based source control, CI/CD pipelines, and automated deployment processes. - Coordinate with Network and Security teams to troubleshoot connectivity and infrastructure issues. - Work with TCP/IP, DNS, routing, firewalls, ports, load balancing, SSL/TLS, NAT, and VPN technologies. - Use Linux networking utilities to investigate connectivity and application performance issues. - Participate in production incident resolution, root-cause analysis, and high-priority deployments. - Maintain technical documentation and communicate solutions across cross-functional teams. ## Required Qualifications - Minimum 5 years of Linux systems administration or equivalent enterprise infrastructure experience. - Strong hands-on experience with Red Hat Enterprise Linux (RHEL) or comparable Linux distributions. - Experience administering and troubleshooting Apache HTTP Server. - Experience with Red Hat JBoss Enterprise Application Platform (EAP). - Working knowledge of Java/Jakarta EE applications and the ability to interpret application logs, stack traces, and JVM errors. - Experience troubleshooting application builds and deployments. - Understanding of Git, CI/CD pipelines, and automated deployment processes. - Strong networking fundamentals, including TCP/IP, DNS, routing, firewalls, load balancing, and SSL/TLS. - Ability to troubleshoot issues across application, middleware, operating system, database connectivity, and network layers. - Strong analytical, problem-solving, communication, and documentation skills. - Ability to collaborate effectively with Development, Infrastructure, Network, Security, and Operations teams. ## Preferred Qualifications Experience using Jira for incident, change, problem, and work tracking. Familiarity with GitLab, Jenkins, Ansible, or similar CI/CD and automation tools. Experience supporting highly available, business-critical enterprise applications. Familiarity with F5 BIG-IP or similar load-balanc