Senior Network Security Engineer

📌 Senior Network Security Engineer

📌 Sheffield or Hatfield

📌 £58,000 to £70,000 + 10% Bonus

📌 10% Pension + Life Assurance + Excellent Benefits + Share Equity

📌 Hybrid Working | 3 On Site | 2 Remote

 ** The business will support the application for security clearance. Due to the nature of work, the individual has to be a UK national or have lived and worked in the UK for the past 5 consecutive years. **

The Role In a Nutshell

Act as the primary technical authority for key customer's complex network and security infrastructure. This is a unique hybrid position blending Technical Design Authority responsibilities with senior operational engineering, requiring deep networking and security expertise to drive technical improvements and lead during critical incidents.

The Business

With one of the largest networks in Europe, this business invests hundreds of millions annually in research each year and employs more than 10,000 people in the network business alone. With incredible opportunities to learn, develop and grow your skills, they will invest in you, nurture your potential and shape your future whatever your background or experience.

The Role

You'll be the dedicated technical resource for key enterprise customers leveraging the IaaS platform to deliver critical business solutions. This isn't standard ticket-based work—you'll drive technical improvements, lead projects, and engage directly with customers. The role is 60-70% technical, requiring subject matter expertise in high-pressure, customer-facing environments. You'll be the go-to expert during major incidents, providing deep technical leadership.

Skills & Experience

• Demonstrable, in-depth experience in networking and security

• Strong skills in LAN switching and routing principles

• Proven experience with security technologies

• Expertise with Fortinet and Cisco highly preferred

• Eligible for UK Security Clearance (SC)

The following would be an advantage:

• Experience with WAF/Load balancers

• Dynamic routing protocols

• FCSS/CCNP or Fortinet Network Security certifications

• Agile and ITIL process knowledge

Your Responsibilities

• Act as lead technical authority for customer's complex infrastructure environments

• Proactively identify and drive technical improvements, projects, and changes

• Serve as primary technical contact during major incidents, leading resolution

• Work directly with customers, managing stakeholder relationships

• Provide technical leadership and oversight for second and third-line support engineers

• Develop deep understanding of customer solutions to implement beneficial changes

Other skills required:

•Technical Authority- Proven ability to articulate design and implementation of complex technical solutions with detailed examples, explaining rationale end-to-end

•Customer Engagement- Exceptional communication and stakeholder engagement skills with ability to build customer rapport and trust

•Problem Solving- Strong analytical abilities, capable of providing deep, low-level technical analysis in pressurised environments

•Leadership- Confidence to lead technical discussions and mentor colleagues, providing trustworthy feedback

•Improvement Mindset- Proactive approach to constantly seeking opportunities to enhance service and efficiency

Benefits

• World-class training and development opportunities

• 10% on-target bonus

• Company Pension scheme

• 25 days annual leave plus bank holidays, increasing with service

• Huge range of flexible benefits including cycle to work, healthcare, season ticket loan

• Option to join company share saving schemes

• Equal family leave: 18 weeks full pay, 8 weeks half pay, 26 weeks statutory rate

keywords: network security, fortinet, cisco, technical authority, customer-facing, security clearance, lan switching, routing, waf, load balancer, fcss, ccnp, infrastructure, technical leadership