Network Security Consultant

Cognizant; Warrington; On-site; GBP 60,000 - 90,000; Full time

Job summary

Cognizant is seeking Network Security Consultants to join its Cybersecurity Practice in the United Kingdom. You will administer and maintain firewall, load balancer, proxy, NAC and MFA technologies, and execute changes through formal change management.

You will support migrations, conduct build/test/cutover activities under L3 direction, maintain rollback plans, and contribute to knowledge bases. You will act as final escalation point across towers, owning design and governance for migrations.

Qualifications

• Experience with firewalls, load balancers, proxies, NAC and MFA in enterprise environments.
• Ability to execute changes via formal change management and resolve incidents per SLA.
• Experience with platform migrations, build/test/cutover activities and rollback planning.
• Comfort working in critical-infrastructure environments with compliance sensitivity.
• Willingness to work across multiple platforms and on-call shifts.

Responsibilities

• Administer and maintain firewall, load balancer, proxy, NAC and MFA technologies.
• Execute changes through change management; test before production; resolve L1/L2 incidents within SLA; perform root cause analysis.

Skills

Firewall admin

Load balancer

Proxy security

NAC

MFA

Incident response

Change mgmt

On-call rotation

Platform migrations

Automation

SIEM/XDR

Vulnerability mgmt

Job description

Excellent opportunity for Network Security Consultants to be part our Cybersecurity Practice.

Key Responsibilities :

• Administer and maintain the assigned technology areas within the estate (firewall, load balancer, proxy, NAC, MFA — assignment may span one or more depending on account staffing needs)
• Execute changes through the formal change management process; validate and test before production implementation. Resolve incidents escalated from L1/L2 within agreed SLA targets; perform root cause analysis on recurring or complex issues
• Maintain accurate configuration, change, and troubleshooting documentation to support audit and compliance requirements Participate in the on-call rotation and respond to P1/P2 incidents outside core hours as required

Migration & transformation support

• Support active platform migrations and decommissions in progress across the account (hardware refreshes, platform replacements, cloud transitions)
• Execute build, test, and cutover activities under L3 direction; L3 owns the technical design and cutover governance
• Maintain rollback/parallel-run plans during transition periods and flag risk to the Team Lead
• Contribute to optimization initiatives (e.g., rule/policy cleanup, dependency mapping, automation of routine tasks). Feed lessons learned and recurring issues into the knowledge base and L1 runbooks

Act as final technical escalation point across all towers, not just area of primary assignment

• Own technical design and governance for platform migrations; review and approve high-risk changes Coordinate cross-practice dependencies with adjacent delivery towers where scope overlaps.

Technical grounding expected :

• Firewall administration and policy management (rule-base changes, VPN tunnel troubleshooting — site-to-site and remote access)
• Load balancer operations (virtual servers, pools, health monitors)
• Proxy/web security administration, including exposure to cloud-delivered secure web gateway/RBI models
• Network access control concepts (802.1X, endpoint profiling) — vendor flexibility expected, as the NAC platform is under active review
• Identity/MFA administration, including cloud identity platforms
• Familiarity with adjacent security tooling used for correlated incidents (SIEM/XDR, privileged access management, vulnerability management, micro-segmentation)

Explicitly required mindset

• Comfortable operating in a critical-infrastructure/utility environment with attendant compliance sensitivity
• Willing and able to work across multiple platforms rather than defend a single-vendor specialism — several core platforms are mid-migration or mid-decision
• Available for the 16×5 shift/on-call model, including rotational off-hours coverage for P1/P2

Certifications

• Vendor firewall/network security associate-level certification (e.g., NSE 4, CCNA/CCNP Security)
• Load balancer or proxy vendor certification where applicable to primary assignment