Network Security Engineer – Network Flow Management

Project overview

Network Security Engineer – Network Flow Management

Main Responsibilities

Required Technical Skills

Behavioral Skills

Profile Sought

Conditions

• Analysis of flow matrices: study each flow request (source, destination, port, protocol, direction, business justification) and verify its compliance with the network architecture, application HLDs and LLDs, and current security rules.
• Authorization/refusal decision: validate or refuse flows according to the principle of least privilege, network segmentation, risk analysis, and internal security policy.
• Mastery of multi-site / datacenter / cloud hybrid flows: analyze inter-site flows, between datacenters (North-South and East-West), and towards Azure cloud (VNet, NSG, Azure Firewall / virtual FortiGate, VPN, ExpressRoute), and ensure consistency of rules between on-premise and cloud.
• Traceability and documentation: record each decision (justification, validity period, requester, review date) in the flow management tools.
• Periodic review and cleanup: regularly audit existing rules, identify obsolete, unused, or oversized flows, and propose their removal.
• Contribution to network security policy: participate in the drafting, updating, and dissemination of segmentation, filtering, and secure architecture standards (zero trust, DMZ, micro-segmentation).
• Audit support: prepare and assist with internal/external audits and compliance checks (ISO 27001, ANSSI, PCI-DSS depending on context).
• Technical watch: follow developments in network threats, vulnerabilities, and market best practices.
• (Additionally) Firewall log optimization: define and optimize firewall logging policy (rules to log, log levels, volume, filtering of logs sent to SIEM / FortiAnalyzer) to improve detection relevance while controlling storage and license costs.
• Solid mastery of network protocols.
• Operational experience with firewalls (Fortinet).
• Knowledge of secure network architectures: segmentation, DMZ, zero trust, micro-segmentation.
• Experience with multi-site and datacenter environments (SD-WAN, site-to-site VPN, interconnections, North-South / East-West flows).
• Knowledge of Microsoft Azure network and security (VNet, peering, NSG, Azure Firewall, FortiGate deployment in Azure environment).
• Mastery of centralized firewall administration (FortiManager or equivalent) and logging/reporting tools (FortiAnalyzer, SIEM, Syslog).
• Ability to analyze and optimize the volume and quality of logs generated by firewalls (event selection, retention, correlation).
• Practice with flow matrix / change management tools (Tufin, AlgoSec, or equivalent) is appreciated.
• Knowledge of repositories and standards: ISO 27001, ANSSI IT hygiene guides, NIST.
• Scripting basics (Python, Bash) for control automation, a plus.
• Knowledge of IDS/IPS and network monitoring (SIEM) solutions is appreciated.
• Rigor, analytical thinking, and attention to detail.
• Ability to clearly document and justify decisions.
• Sense of responsibility regarding the company's security challenges.
• Good interpersonal skills for dialogue with infrastructure, application, and business teams.
• Autonomy and ability to manage priorities in a context of multiple requests.
• Master's degree (engineering school or university) in IT security, networks, or telecommunications.
• 2 to 5 years of experience in a similar role (network engineer, network security, or SOC), level adjustable according to the target position.
• Appreciated certifications: CCNA/CCNP Security, Fortinet NSE, Microsoft AZ-700 (Azure Network Engineer)
• Long-term mission
• Duration: 3 months renewable
• Location: Paris La Défense
• Remote work: 2 days

Project details

• Start: 2026-10-26
• Duration: 36 mois
• Location: 92400 COURBEVOIE, FR
• Languages: French