Unix/Linux DevOps with Java Expertise - C

About Proximus NXT

Proximus NXT Luxembourg supports all organizations in their digital transformation, by providing holistic ICT & Telecommunication solutions, as well as tailored managed services. With our partners and customers, we co-create opportunities and enable growth in a secure and sustainable manner. As a result of our unique expertise in next-gen IT services, mobile and advanced connectivity, we help our customers achieve their ambitions and realize their vision.

Together with them and our partners we implement sovereign and trusted solutions that make people work smarter.– www.proximusnxt.lu

Your mission :

Overview: We are seeking a Unix/Linux DevOps with Java application support expertise to maintain, optimise, and secure the underlying infrastructure for our hosted Atlassian Jira/Confluence environments. This role focuses on server administration, performance tuning, and troubleshooting in a Linux (RHEL)-based ecosystem, ensuring high availability, security, and compliance for enterprise-scale deployments.

You will manage the Unix/Linux infrastructure, support Java-based applications (Jira/Confluence), and collaborate with Atlassian administrators to resolve system-level issues. Your expertise in Linux, Java, and web application servers will be critical to maintaining stable, performant, and secure environments.

Key Responsibilities:

1. Unix/Linux System Administration
   • Administer and optimise RHEL-based servers hosting Jira, Confluence, and related Atlassian tools.
   • Manage user permissions, disk space, logging, and system monitoring to ensure operational stability.
   • Automate routine tasks (Bash, Python, Perl) for deployments, backups, and log analysis.
   • Troubleshoot OS-level issues, including performance bottlenecks, resource contention, and connectivity.
2. Java Application & Web Server Support
   • Support Java-based applications (Jira/Confluence) running on Tomcat, including JVM tuning, memory optimisation, and garbage collection.
   • Configure and maintain Apache HTTPD/Tomcat, including reverse proxy setups, SSL/TLS certificates, and load balancing.
   • Monitor application logs (Catalina, access/error logs) to diagnose and resolve issues.
   • Collaborate with Atlassian administrators to apply patches, upgrades, and security fixes (CVEs).
3. Database & Integration Management
   • Troubleshoot JDBC connections and optimise database queries impacting application performance.
   • Support integrations with LDAP/SSO (Crowd, EULogin), CI/CD tools (Bamboo, Jenkins), and monitoring systems.
4. Security & Compliance
   • Enforce security best practices, including hardening Linux servers, managing firewalls, and applying patches.
   • Ensure compliance with enterprise security policies, including access controls, encryption, and audit logging.
   • Collaborate with security teams to mitigate vulnerabilities and respond to incidents.
5. Performance & Scalability
   • Optimise system performance through Linux tuning, resource allocation, and Java/JVM adjustments.
   • Assess and recommend scalability improvements (e.g., clustering, high availability).
   • Monitor system metrics (CPU, memory, I/O) and proactively address bottlenecks.
6. Documentation & Collaboration
   • Document system configurations, troubleshooting steps, and operational procedures.
   • Provide technical guidance to Atlassian administrators and support teams on infrastructure-related issues.
   • Participate in change management (e.g., upgrades, migrations) to minimise downtime.

Your profile :

Required Skills & Experience:

• • Technical Skills (1-to-5 scale)
    • Linux (RHEL) Administration: 5
    • Java/JVM Tuning: 5
    • Apache HTTPD: 4
    • Tomcat: 4
    • PostgreSQL: 4
    • Bash Scripting: 4
    • Python/Perl: 3
    • SSL/TLS & HTTP/HTTPS: 3
    • JDBC & Database Optimization: 3
    • LDAP/SSO: 3
    • CI/CD (Bamboo, Jenkins): 3
    • Monitoring & Logging: 3
    • Security Hardening: 3
    • Atlassian Tools (Jira/Confluence): 2
  • Soft Skills
    • Analytical and problem-solving mindset for system-level issues.
    • Strong communication skills to collaborate with cross-functional teams.
    • Proactive and detail-oriented, with a focus on system reliability and security.
    • Ability to document processes and share knowledge effectively.
  • Experience
    • 5+ years of Unix/Linux (RHEL) system administration in enterprise environments.
    • Strong experience with Java applications, including JVM tuning, Tomcat administration, and troubleshooting.
    • Hands-on knowledge of web servers (Apache/Tomcat), databases (PostgreSQL), and scripting (Bash, Python).
    • Familiarity with Atlassian tools (Jira/Confluence) from an infrastructure support perspective.
    • Experience with security best practices, including firewalls, encryption, and compliance audits.
    • Knowledge of CI/CD pipelines (Bamboo, Jenkins) and integration with monitoring tools.

Mandatory Requirements:

• • EU citizenship;
  • Fluency in English (written and spoken) is required; proficiency in any other European language is a plus.

Our offer :

A professional and stimulating work environment in the IT & telecom sector. Multiple career opportunities within the Proximus Group at national and international level, cutting-edge training in new technologies, a wealth of recognized expertise. We also offer an attractive salary package and many other benefits.

Our company is an equal opportunity employer, valuing diversity in all its forms. We firmly believe that each individual brings a unique richness to our teams, and we are committed to creating an inclusive environment where every voice counts.

If at the end of the process your application is successful, you will be asked to provide an extract from your criminal record. Your personal information will be handled in compliance with applicable data protection laws.