Core Network Engineer

As a key member of our Government Security team, you’ll be at the heart of protecting our customers and supporting critical national security work. You’ll oversee the day‑to‑day operation of VMO2’s Security function, ensuring our systems run smoothly, securely, and in full compliance with legal obligations. Working as part of a small close‑knit team, you’ll support customers, lead complex fault investigations, carry out integration and verification testing, and play an important role in shaping future capabilities. You’ll work across core network technologies, collaborate with internal teams and external vendors, and contribute to major new projects that keep our networks safe and resilient.

This is a role for someone who enjoys variety, isn’t afraid to roll their sleeves up, and thrives on learning new things as technologies and demands evolve. Some days that will mean testing across multiple services, troubleshooting complex issues, and helping to drive improvements. Others you’ll be leading on project work. You’ll define testing scope for existing and emerging technologies, coordinate with suppliers, and provide clear updates to project and stakeholder groups. Strong relationships with internal and external customers will be key to ensuring seamless delivery and a high‑quality operational service.

The must haves

In order to be considered, you must have the following experience.

• Demonstrates working knowledge of mobile networking (packet core, IMS, and voice core).
• Apply complex fault analysis and resolution techniques to restore service swiftly.
• Ability to learn quickly and adapt to new challenges with minimal guidance.
• Handle and manage conflicting priorities instinctively.
• Works well within a team and operates effectively without supervision.
• Demonstrates a strong troubleshooting methodology.
• Communicates effectively and collaborates across teams within VMO2, including engaging with senior leadership as required.
• Proficient in Linux system administration.
• Create high‑quality technical documentation.
• Implements health‑check monitoring and automation schedules to ensure operational integrity.
• Has exposure to operational monitoring and troubleshooting tools (e.g., Zabbix, Grafana).
• Provides support for operational testing and system integration activities.
• Awareness of the Investigatory Powers Act 2016 (IPA) and its implementation.

The other stuff we're looking for

We'd also love you to bring;

• This role requires you to undergo and obtain UK Government Security Clearance
• A natural curiosity and a methodical approach, enabling you to get to the root cause of problems quickly and confidently.
• You’re comfortable analysing complex technical situations, asking the right questions, and using data and evidence to guide your decisions.

What's in it for you?

As you're already a valued member of the Virgin Media O2 crew, you'll know lots about the amazing stuff we do to take care of our people. If you need a reminder, head on over to the benefits portal via the main intranet site.

Next steps

Once you've applied the next steps of the process, if successful, are likely to include {*outline what the process is likely to include*}.

This opportunity is open to all employees. However, we will be prioritising any at risk employees who meet the minimum criteria which are outlined above.

{*Remove this section if not a change role*} Adverts will be running for a 2-week period, so please be aware that you may not hear from us until the advert has closed.

If you’ve got any burning questions or require reasonable adjustments to support you through the recruitment process, please drop the recruiter a note.