Security Engineer - Network Domain
First seen by Alion on Oct 23, 2026.
About the Role:
Expleo is a trusted partner for end-to-end, integrated engineering, quality services, and management consulting for digital transformation. As part of the Expleo UK Cybersecurity Practice, you will join a managed Cyber Operations service for a major UK energy network operator that forms part of the UK's Critical National Infrastructure (CNI).
As a Security Engineer | Network, you will provide design, review, and analysis expertise across the client's firewalls, intrusion prevention, secure web gateway, and remote access controls. This is a design, review and advisory role working within Expleo's offshore consultancy team.
Responsibilities:
- Assess firewall, intrusion prevention and gateway change requests for security risk and design quality.
- Carry out quarterly firewall rule-base reviews using configuration exports.
- Analyse network security log and alert reporting monthly and during incidents.
- Track intrusion prevention signature releases and advise on critical updates.
- Contribute to secure web gateway, remote access and CASB policy design and review.
- Review network segmentation and IT/OT boundary controls.
- Define audit logging requirements for network security devices.
- Produce internet access usage and network security reports.
- Maintain network security infrastructure diagrams and configuration documentation.
Qualifications :
- Degree in computer science, networking, cybersecurity or a related discipline, or equivalent professional experience.
- Vendor firewall certification (e.g. PCNSE or Fortinet NSE 4 or above).
- CompTIA Security+, CySA+, CCNP Security, or an SSE/SASE vendor certification would be advantageous.
Essential Skills :
- Next-generation firewall design and rule-base review (e.g. Palo Alto, Fortinet, Check Point).
- Intrusion prevention and network detection technologies (e.g. Trend Micro TippingPoint, Cisco Firepower, Darktrace).
- Secure web gateway, SSE/SASE and remote access (e.g. Prisma Access, Zscaler, Netskope).
- TCP/IP, routing, VPN, network segmentation and IT/OT boundary concepts.
- Security log analysis and ITIL change and incident processes.
What Do I Need Before I Apply :
- Right to work in India and based in or willing to relocate to Chennai.
- Willingness to complete Expleo enhanced pre-employment background screening.
- Ability to work hours that overlap with the UK business day.
- Excellent written and spoken English.
Skills
IT Security Strategy, Security Protocols, Security Tools, Network Security, Cyber Security, Firewall, Security Configuration, CompTIA Security, CSA, IT Audit