TL;DR

Mobile Core Design Specialist (Telecommunications): Designing and delivering mobile core network signalling and roaming solutions within the Mobile Core Design department. With an accent on high-availability signalling nodes and international roaming services. Focus on designing complex signalling architectures, guiding cross-team collaboration, and shaping long-term solution strategies.

Location: Hybrid in London or Bristol, United Kingdom (3 days in office, 2 days remote)

Company

BT Group is a leading UK telecommunications corporation, home to brands like BT, EE, Openreach, and Plusnet, driving the UK’s largest digital infrastructure projects and 5G rollout.

What you will do

  • Deliver deep technical and repeatable signalling design solutions meeting customer requirements.
  • Guide partnerships with business and operational stakeholders to ensure smooth transition from design to operational acceptance.
  • Create and maintain robust design documentation and identify critical dependencies.
  • Provide thought leadership and advice on technologies shaping long-term architecture strategies.
  • Lead complex strategic initiatives aligned with company commercial strategy.
  • Continuously develop domain expertise and share knowledge on emerging trends.

Requirements

  • Location: Must be based in or able to work hybrid from London or Bristol, UK
  • Strong experience in mobile core network solution architecture and design of signalling nodes (STP, Diameter DRA, SIP routers, 5G SBA SCP/SEPP).
  • Experience with signalling and voice interconnects, MVNO networks, international roaming, and value-added services.
  • Proven ability to manage supplier relationships and deliver products into production.
  • Ability to analyze requirements and document recommended solutions clearly.
  • Experience managing transitions from design through delivery to operational acceptance and performance monitoring.

Nice to have

  • Knowledge of cloud computing for mobile signalling solutions.
  • Membership in professional bodies such as the Institution of Engineering and Technology.
  • Degree in relevant engineering discipline.

Culture & Benefits

  • Competitive salary with 10% on-target bonus and excellent benefits including pension scheme and life assurance.
  • Flexible working style with hybrid model (3 days office, 2 days remote).
  • Generous family leave policies and enhanced women’s health support.
  • 25 days annual leave plus bank holidays, increasing with service.
  • Access to private virtual GP appointments and carer’s leave.
  • Discounts on BT broadband, TV, and mobile plans.