Contract Details: Freelance(6 months with high probability of further extension)

Hybrid work: 2 days from home, 3 days from the clients office from Bucharest.

Seniority: Mid-Senior Level

Language: Excellent English (spoken & written)

Role Overview

We are seeking a skilled Network Security Engineer to manage, maintain, and enhance our network security infrastructure. The ideal candidate will have solid hands-on experience with Cisco Firewalls (ASA & Firepower), strong networking fundamentals, and the ability to support a complex enterprise network. This role is critical in ensuring security, stability, and performance across all network layers.

Key Responsibilities

Firewall & Security Management

• Manage Cisco ASA and Firepower firewalls, ensuring compliance with security policies and operational standards.

• Operate and maintain IDEMIA firewalls, centrally managed by the Network Security team.

• Create, modify, and remove filtering rules based on ticket requests, ensuring appropriate validation from Security and Compliance.

• Administer firewalls through FMC (Firepower Management Center), handling configuration updates, security hardening, and optimizations.

• Apply system configurations and enforce security hardening for new firewalls.

Network Operations

• Configure and manage routers, switches, firewalls, and load balancers to support stable network performance.

• Monitor network activity, detect anomalies, investigate incidents, and troubleshoot issues proactively.

• Oversee network performance using tools such as Wireshark, SolarWinds, Cisco IOS/NX-OS.

• Ensure robust and secure operations through best practices in TCP/IP, VLANs, VPNs, BGP, OSPF, and overall network security.

Collaboration & Support

• Work closely with system engineers, project managers, and external vendors to integrate network components into larger infrastructure projects.

• Provide guidance and support to IT teams submitting firewall rule requests.

• Participate in infrastructure upgrades, migrations, and new deployments.

What You Bring

Education & Experience

• Bachelors degree in Computer Science, Software Engineering, or a related field (preferred).

• 3-5 years of hands-on experience in a similar networking/security role.

• Strong foundational knowledge of networking principles and enterprise-grade infrastructure.

• Experience managing complex network environments, ideally in infrastructure-heavy or construction-related industries.

Technical Skills

• Mandatory: Practical experience managing Cisco ASA Firewalls (configuration, troubleshooting, policy management).

• Hands-on experience with Cisco Firepower, FMC, and firewall administration.

• Expertise in:

  • TCP/IP

  • VLANs

  • VPNs

  • BGP, OSPF

  • Network security best practices

• Proficiency with troubleshooting & monitoring tools:

  • Wireshark, SolarWinds, Cisco IOS/NX-OS

• Knowledge of cloud networking (AWS, Azure, GCP) and SD-WAN technologies is a strong plus.

Certifications (Highly Desirable)

• CCNA

• CCNP

• Or equivalent networking/security certifications.

Soft Skills

• Strong problem-solving and analytical capabilities.

• Proactive mindset and ability to anticipate and resolve network issues.

• Excellent communication skills for interactions with both technical and non-technical stakeholders.