Job Description
Mobile Core Design Specialist - Subscriber Data Management
Req ID:  57260
Posting Start Date:  21/04/2026
Job Function:  Engineering
Division:  Networks
Job Location:  GBR-London-BTHQ One Braham
Advertised Salary:  .

Hiring Manager: Inigo Mendizabal 

Career Grade: D 

Internal Closing Date: 30/4/26 

Why this job matters

Our mobile network is currently the best performing in the UK, according to external benchmarking reports. And we intend to keep it that way.   

You’ll be working across multiple technologies, including 2G, 3G, 4G, 5G, Wi-Fi & Fixed telephony. Meaning the networks you’re working on, have a direct impact on over 27 million users. You’ll help to  deliver and maintain network services, as well as support platform and application design and capacity management not just for business as usual, but projects too.  

The Subscriber Data Management domain in the Mobile Core is responsible, but not limited to, for the following network functions: HSS and HLR, UDM, AUSF, UDR and UDSF, AAA, SPR, Location Based Services, EIR, and the Element Management functions in the domain. 

What you’ll be doing

  • Acts as technical expert and design authority, and designs solutions that are scalable, adaptable & cost effective in line with business needs and manage the integration of the design.
  • Analyses network capacity and performance, creates plans for  platform and application evolution to meet functional and non functional requirements, and inputs into the budget planning. 
  • Produces and maintains high level and low-level quality design documentation for platform and application levels. 
  • Works closely with the project office, test, operational, other design teams, and wider stakeholder to communicate and resolve delivery plans, issues and solve complex business requirements.  
  • Provides in-life and in -delivery support for issues related to the solution and root cause analysis.  
  • Champions, continuously develops and shares with team knowledge on emerging trends and changes in solution architecture and design.​ 
  • Mentors other designers, helping to improve the team’s abilities by acting as a technical resource​. 

 

Experience

  • Knowledge and experience in solution architecture and system design, networking protocols, software deployments on containers, and/or Linux.  
  • Analytical skills for troubleshooting and low-level diagnostic ability.  
  • Strong communication skills.  
  • Able to show that you’re comfortable working with ambiguity and independently.  
  • Roadmapping/planning, and Service Delivery: maps strategic requirements for the solution and/or system in a visual way and manages the solution architecture design, implementation and delivery ensuring alignment with key objective and overall business direction 
  • Cloud Computing : uses cloud technologies in the solution architecture to create value. 

Experience you’d be expected to have 

  • 5 year experience in Mobile Subscriber Data Management applications and platform design, planning and delivery. 
  • 3 year experience in K8s and conteinarised software deployments. 
  • experience in CI/CD and DevSecOps. 

The skills you’ll need

System Design
Regulatory Compliance
Resourcing
APIs/Web Service Integration
Requirements Gathering
Change Management
Product Roadmapping
Risk Management
Technology Deployment
Solution Design
Cloud Computing
Performance Monitoring
Bid Management
Project/Programme Management
Solution Architecture
Decision Making
Growth Mindset
Inclusive Leadership

Our leadership standards

Looking in:
Leading inclusively and Safely
I inspire and build trust through self-awareness, honesty and integrity.
Owning outcomes
I take the right decisions that benefit the broader organisation.

Looking out:
Delivering for the customer
I execute brilliantly on clear priorities that add value to our customers and the wider business.
Commercially savvy
I demonstrate strong commercial focus, bringing an external perspective to decision-making.

Looking to the future:
Growth mindset
I experiment and identify opportunities for growth for both myself and the organisation.
Building for the future
I build diverse future-ready teams where all individuals can be at their best.

BT Group is the UK’s leading communications group and the holding company behind some of the country’s most recognised brands – including BT, EE, Openreach and Plusnet. Our purpose is as simple as it is ambitious: we connect for good.  Our customers include consumers, small, medium and large businesses, public sector organisations and other communications providers. 

BT Group’s role is about setting direction, unlocking value and creating the conditions for our brands and businesses to thrive.

Having come through the most capital-intensive phase of our fibre investment, our focus now is on what comes next – simplifying how we operate, using technology and AI to work smarter, and organising ourselves to serve customers better and grow sustainably. Group teams shape strategy, policy, brand, capital allocation and transformation, helping the whole organisation perform at its best.

We have a singular culture that unites all our people: we are customer-first challengers, who are committed, clear and connected. These behaviours unite us as one team to deliver for our colleagues, our customers, our stakeholders and the country.   Joining BT Group means working at the heart of a business that matters to the UK, with the opportunity to shape decisions, influence outcomes and help set the future course of one of the country’s most important companies.