Software Engineering Specialist

We are driving the modernisation of Core Voice Network platforms, transforming legacy telephony systems into scalable, cloud-native, microservices-based architectures while also enabling next-generation Voice AI capabilities such as intelligent call handling, automation, and conversational services.

This role sits within a Software Engineering Development team focused on designing, developing, and evolving distributed applications that underpin call services and routing across BT's fixed voice estate. You will play a key role in building and shaping microservice architectures, leveraging technologies such as Java, Spring Boot, Podman, and Kubernetes, and contributing to system design for high availability, scalability, and real-time processing. Working closely with cross-functional teams, you will help deliver robust, production-grade solutions, mentor engineers, and continuously improve development practices.

This role is based at New Bailey, Manchester, UK with a hybrid working model of 3 days together, 2 days wherever.

What you'll be doing

• Design, develop, and maintain scalable microservices-based applications using Java, Spring Boot, and containerisation technologies (Docker, Kubernetes)

• Define and implement RESTful APIs aligned to OpenAPI (Swagger) standards to support digital and distributed systems

• Lead by example through hands-on development, while reviewing code and mentoring engineers to ensure high-quality delivery

• Adopt an AI-first engineering approach, leveraging AI tools and Voice AI capabilities to accelerate development, improve code quality, and enable intelligent call handling solutions

• Collaborate with architects, product teams, analysts, and engineers to deliver solutions across component and end-to-end system levels

• Contribute to system design and architecture, ensuring scalability, resilience, and performance for real-time, high-throughput platforms

• Solve complex technical issues, performing coding, debugging, testing, and troubleshooting across the application stack

• Conduct deep-dive analysis to identify bottlenecks, optimise performance, and reduce technical debt through continuous improvement

• Contribute to and help shape the technical roadmap, aligning engineering deliverables with business objectives and innovation trends

• Champion best practices and continuously share knowledge on emerging technologies, including AI-driven development approaches

• Exposure to Core Voice platform development (e.g., OCCAS) including working with telecom protocols and tools such as SIP signalling, RTP media flows, traffic simulation (SIPP), and troubleshooting using tools like Wireshark is desirable but not mandatory

• Strong experience in Java development with good working knowledge of Spring Boot, along with experience in designing and building production-ready APIs using OpenAPI (Swagger)
• Good understanding of microservices architecture patterns, distributed system design, and experience working with relational databases (such as MYSQL/Timesten) for scalable solutions
• Understanding of container technologies such as Docker, comfort working in Linux environments with basic Bash scripting, along with working knowledge in AI concepts and frameworks within software development

Desirable Skills / Experience

• Experience using Git for version control. Awareness of continuous integration and delivery (CI/CD) practices
• Familiarity with tools like Consul and Prometheus for service discovery and monitoring
• Strong foundational knowledge of Container as a Service, including its key components and how it supports scalable applications
• Experience working in Agile teams, using tools such as Jira and Scrum practices
• Familiarity with cloud platforms (such as AWS, Azure, or OpenStack) and virtualised environments
• Experience working with telecom or voice systems
• Exposure to Core Voice platform development (e.g., OCCAS), including working with protocols and tools such as SIP signalling, RTP media flows, traffic simulation using SIPP, and troubleshooting with tools like Wireshark

Tailored benefits make a real difference. That's why we offer a comprehensive range to support your growth, wellbeing, and everyday life.

You can design the package to suit you and your lifestyle. Your core benefits include:

• 10% on target annual bonus
• Access to an online private GP 24/7 for you and your immediate family
• Market-leading paid carers leave with up to 2 weeks off
• Equalized maternity, paternity, and adoption leave - 18 weeks' full pay and 8 weeks' half pay
• Discounted EE and BT products, including mobile and broadband
• Market leading Pension scheme - 5% from you and 10% from us
• Holiday purchase scheme

You can select additional benefits, including healthcare, dental, gym memberships and more when you're ready.

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.