3rd Line Network & Security Specialist - 24x7 Shift

The BT Group is hiring for a 3rd Line Network & Security Specialist to join the Bespoke Operations team on site at a secure customer facility in Derby. This is a full-time, on-site role within the Security & Network Engineering function, working alongside BT colleagues and third-party engineers in an air-gapped environment. The aim is to drive down KPIs and SLAs while handling complex security issues and projects, with a strong emphasis on customer experience and technical leadership.

This position suits someone who thrives on direct customer engagement, has hands-on experience in both network engineering and security operations, and wants to be the technical lead on security matters. It’s a 24x7 on-site role that requires coordinating with multiple stakeholders to protect critical services and to keep operations running smoothly in a demanding, on-premises setting.

BT Group is driving a multi-year transformation to modernise at scale, expand into new markets, and deliver value through cyber, AI and managed services. The role sits at the heart of this shift, offering the chance to influence long-term security outcomes for a key customer while contributing to BT’s broader goals in a fast-moving UK technology and telecommunications landscape.

Your Day To Day As A 3rd Line Security Specialist

You will be a Subject Matter Expert for a wide range of technologies and security products, guiding design and operational decisions. You’ll detect, respond to and resolve complex security incidents, problems and changes within the live environment, working with stakeholders to ensure timely and effective outcomes.

On the ground, you’ll provide 3rd line support for high-priority incidents and drive resolution within agreed SLAs. You’ll also act as the operational single point of contact for design or customer contract teams, delivering root cause analyses and contributing to post-incident reviews when required.

The Right Candidate For This BT Role

Must-have qualifications:

• Proven operational experience across Network Engineering and Security Operations Specialist roles, with strong stakeholder management skills and the ability to work directly onsite with customers to support complex network solutions
• Proven experience across Cisco Firewalls, Checkpoint Firewalls/IPS, F5 Load Balancing, Cisco WSA / ESA / ISE, Ivanti Pulse VPN, Switches and Routers, supported by industry recognised certifications or relevant experience
• Ability to lead and manage major or complex security & network incidents, coordinating teleconferences and liaising with designers and wider teams to troubleshoot, fault-find and drive resolution

Nice-to-have qualifications:

• Exposure to ServiceNow reporting and dashboarding
• Experience with Fortinet Firewalls and NetScout
• Excellent experience of managing multiple incidents as a lead, making the right decision to resolve within agreed SLAs

Pay, Benefits And Working Details

BT offers a comprehensive benefits package designed to support growth, wellbeing and everyday life. Highlights include a 10% on-target annual bonus, access to an online private GP available 24/7 for you and your immediate family, and market-leading leave policies for carers. The company also provides equalised maternity, paternity and adoption leave, 18 weeks of full pay and 8 weeks of half pay, plus a pension scheme with 5% employee contributions and 10% employer contributions. Additional perks include discounted BT products, a holiday purchase scheme and the option to add healthcare, dental, gym memberships and more as you choose.

This is a fully on-site role with no home working, and you’ll be part of a 24x7 security team providing in-life technical support. The shift pattern is 2 days, 2 nights, 4 days off, on a 7-7 cycle.

Location is Derby, on-site at a BT customer site in the UK. The role requires eligibility to gain and hold Government Security Clearance to SC UK Eyes Only Level, with potential future DV clearance. The environment is air-gapped and security-focused, reflecting the sensitive nature of the work.

Advice For Applicants

Put your strongest proof of on-site, customer-facing network and security operations up front on your resume. Lead with examples that show you’ve worked directly with customers to support complex network solutions and to resolve high-priority incidents.

Demonstrate how you’ve proven the essential skills listed here: hands-on experience with Cisco Firewalls, Checkpoint, F5, WSA/ESA/ISE, Ivanti Pulse VPN, and core switching and routing hardware, plus any relevant certifications. Concrete incidents where you led the response and coordination will land well.

Be ready to talk through how you handle major or complex incidents, including how you run teleconferences, coordinate with designers and broader teams, and deliver root cause analyses and PIRs when needed. Having a clear example of a structured incident lifecycle will help you stand out.

Ask a smart question about the role’s 24x7 shift coverage, on-site clearance processes, and the current types of security incidents the team is handling. For instance: what’s the typical mix of incidents this client sees, and how does the team collaborate with the design and contract teams during a major event?