Senior Network Security Engineer

About Justera Group
Justera Group AB is a leading Swedish IT consulting firm with great experience specializing in building high-performing technology teams and delivering end-to-end IT solutions. Led by dynamic female executives, Justera Group focuses on helping businesses harness the power of digital technologies to continuously evolve in today’s rapidly changing economy. The company has deep expertise in IT consultancy, software development, and recruitment services, providing clients with purpose-driven, well-trained consultants who consistently deliver efficient and effective results. Justera Group manages the entire talent lifecycle, from hiring to ongoing management, ensuring the right fit for each project on time and within budget. With their strong commitment to quality, collaboration, and client success, Justera Group is a trusted partner for technology innovation across Sweden.

About the Role:
Justera is currently recruiting a Senior Network Security Engineer (Level 3) on behalf of one of our clients, a global leader in industrial innovation. This is a critical, high-impact position based at the client’s headquarters in Södertälje.

As an on-site L3 expert, you will be the senior technical point of contact for enterprise-grade Fortinet firewall operations. You will sit at the heart of the network security team, bridging the gap between operational support and high-level architecture. This role is designed for a "hands-on" expert who thrives on resolving complex, cross-domain incidents and ensuring the absolute stability of a mission-critical security environment.

Key Responsibilities:

• Advanced Operational Support: Resolve complex security incidents involving Fortinet infrastructure, network overlays/underlays, and BGP/OSPF routing connectivity.

• Deep Diagnostics: Perform expert-level packet inspection, session-level troubleshooting, and system diagnostics for HA (High Availability) clusters.

• Change Management: Design and execute non-standard, high-risk changes aligned with HLD/LLD templates and ITIL frameworks.

• Service Optimization: Lead Root Cause Analysis (RCA) for recurring issues and proactively identify architectural improvements to enhance resilience and security posture.

• Vendor & Architecture Liaison: Act as the primary escalation point for Fortinet TAC and work closely with internal L4 Architects on project onboarding and design reviews.

• Mentorship: Provide technical guidance and best practices to L1 and L2 support teams.

Mandatory Technical Qualifications:

• Experience: Minimum 5+ years of experience operating enterprise-grade security environments (Data Center focus).

• Certification: Must hold a valid Fortinet Certified Professional (FCP) or NSE 4-6 equivalent (Credly badge or PDF proof required).

• Fortinet Stack: Proven hands-on mastery of FortiGate, FortiManager, FortiAnalyzer, and SD-WAN.

• Network Fundamentals: Strong command of Layer 2–7 packet analysis, vulnerability remediation, and multi-domain traffic flows.

Preferred (Nice-to-Have):

• Fortinet Certified Solution Specialist (FCSS/NSE 7).

• Experience with Check Point firewalls (CCSA or CCSE certifications).

• Familiarity with SIEM and NMS monitoring platforms.

Logistics:

• Location: 100% Onsite at Södertälje Headquarters.

• Type: Full-time, Permanent.

• Schedule: Local operational hours, with availability for extended support during major incidents or planned maintenance windows.

• Reporting: Reports to the Network Security Operations Manager with a dotted line to the L4 Architecture team.

What We Offer:

• A dynamic and innovative workplace driving advancements in cutting-edge robotic technologies

• The opportunity to collaborate with talented cross-functional teams on meaningful and impactful projects

• Competitive compensation and comprehensive benefits package

• A supportive culture that fosters continuous learning, growth, and professional development

• Flexible hybrid working model for an optimal work-life balance

• 25 days of annual leave to recharge and relax

• An annual wellness allowance of 3,500 SEK to support your health and wellbeing