3rd Line Senior Core Network Engineer in Cardiff

At BUUK Infrastructure, our vision is to be the leading utility partner to accelerate the UK towards net zero for all our customers. Our group of companies has been the major drive for change and innovation over 30 years. We provide a supportive environment that is committed to enabling our people to be the best, ensuring they feel proud to be themselves and part of BUUK Infrastructure.

Open Fibre Networks (OFNL), part of the BUUK Group, is looking for a 3rd Line Senior Core Network Engineer who would like to help us reach our mission to earn customer loyalty and drive business growth by providing consistently excellent service. OFNL is continuously growing both their network and customer base, and this is a new role to the business to assist with their continued expansion. This role is hybrid and based in our offices in central Cardiff.

As the 3rd Line Senior Core Network Engineer, your key responsibilities are:

• Hands-on, senior-level engineering position focused on maintaining, troubleshooting, and developing our MPLS/OSPF-based core IP network.
• Manage, operate and develop OFNL network environment, working to achieve 99.9% service availability, whilst always providing a high level of customer service.
• Responding to outages and major incidents, providing 3rd line support and analysing root cause.
• Perform necessary change management, whilst minimising customer impact.
• Maintain and upgrade the Core network, working with both internal and external stakeholders to maintain network operations.
• Act as a senior technical mentor within the team, supporting upskilling and training, whilst also being point of escalation for the team.
• Be part of escalation on-call rota to ensure 24/7 coverage, which will include planned and unplanned maintenance to the network.

About you:

• Extensive experience in telecoms/network operations with a strong focus on service provider networks.
• Nokia NRS II Certification or equivalent, Juniper/Cisco is desirable.
• In-depth knowledge of MPLS, OSPF, BGP, VRFs, L2/L3 VPNs, QoS, and high-availability architecture.
• Strong troubleshooting and diagnostic skills in large-scale, multi-vendor environments.
• Familiarity with network monitoring (SNMP, NetFlow, etc.) and configuration management tools.
• Clear communication, documentation, and leadership skills.
• Knowledge of access control models and network security.
• Can work well under pressure, whilst maintaining a high attention to detail.
• Proactive team player, willing to contribute to other activities according to demand.

The interview is carried out over 2 stages, both via Microsoft Teams and in person at our Cardiff office. There will be both written and verbal assessments, alongside a small presentation to showcase your technical knowledge. If you require or need any reasonable adjustments to be made to enable you to take part in / attend the interview or interview process, please do not hesitate to let us know how we can best support you.

What can you expect from us:

• At least the cost of living pay increase every year.
• Company pension contributions up to 10% if employees contribute 5%.
• 33 days holiday including bank holidays with the ability to purchase an additional 2 weeks.
• Enhanced maternity, paternity and adoption pay.
• To say thank you, each time you successfully refer someone you will receive a referral payment of £1000 (net of tax).
• Hybrid working for eligible roles.
• Development opportunities to reach your career aspirations.

BUUK has an award-winning culture. We care about your wellbeing and safety as we all deserve the right to go home safe, every day. We are proud to be an equal opportunity employer, we respect each other and advocate for equity, diversity and inclusion in all we do. Please ask us about flexible working options.

For more information please contact our resourcing team on 01359 308260.