Freelance Mission - System Security Administrator (H / F)

POSTE

Our client, a leading IT service provider within a major European banking group, is seeking an experienced Network Administrator to strengthen their Facility Management Department. In this role, you will be responsible for the operation, support, and enhancement of the network infrastructure, ensuring high availability, security, and performance across the organization.

This is a critical role that requires a strong technical foundation, proactive mindset, and the ability to collaborate across teams to maintain and optimize a complex network environment.

Key Responsibilities

• Administer and maintain enterprise-level network systems : routers, switches, firewalls, and wireless access points.
• Monitor network performance, troubleshoot issues, and implement solutions to reduce downtime and latency.
• Collaborate with internal teams for network design, implementation, upgrades, and capacity planning.
• Conduct regular audits and assessments to ensure compliance with internal policies and industry standards.
• Provide Tier 2 / 3 support for network-related incidents and service requests.
• Implement and manage security protocols including VPNs, firewalls, and intrusion detection systems.
• Maintain accurate and up-to-date documentation of network configurations and procedures.
• Ensure business continuity by managing network backups and validating system integrity.
• Work closely with Facility Management and IT teams to ensure seamless service integration.

PROFIL

Required Skills & Experience :

• Bachelor's degree in IT, Computer Science, or equivalent professional experience.
• Proven track record (5+ years) as a Network Administrator or Network Engineer.
• Deep understanding of network protocols : TCP / IP, DNS, DHCP, VPN, etc.
• Proficiency in managing network devices (Cisco, HP, Fortinet, etc.).
• Strong grasp of network security best practices, including firewalls and intrusion detection.
• Familiar with backup and disaster recovery procedures related to network infrastructure.
• Ability to diagnose and resolve complex network issues independently.
• Strong communication and documentation skills in a cross-functional environment.
• Capable of working under pressure and meeting tight deadlines.

Nice to Have :

• Certifications : Cisco CCNA, CompTIA Network+, or similar.
• Prior experience in the banking or financial services sector.
• Knowledge of ITIL frameworks and familiarity with ServiceNow or similar ITSM tools.