Sr. Software Engineer

As a Senior Engineer - Telecom Billing, you will design, build, and support scalable, highly available software systems that power T-Mobile's billing and customer service platforms. You will work hands-on with core telecom billing applications, contributing to system modernisation, performance, and reliability, while exercising strong engineering judgment to diagnose and solve complex, often ambiguous technical problems.

In this role, you are expected to operate with a high degree of autonomy, working through unclear requirements and evolving problem spaces without reliance on step-by-step direction. You will make thoughtful design choices across distributed systems, balancing performance, reliability, maintainability, and scalability trade-offs in mission-critical environments.

You will collaborate closely with cross-functional engineering teams to deliver well-integrated solutions that align with business objectives and technical standards, while also influencing system design, production stability, and long-term architectural direction of T-Mobile's billing platforms.

Responsibilities:

• Design, develop, test, and deploy software solutions supporting large-scale telecom billing and customer service platforms.
• Diagnose and resolve complex, systemic, and unclear production issues across distributed components, APIs, databases, and middleware layers.
• Work effectively in ambiguous problem spaces, independently breaking down problems and driving solutions without prescriptive guidance.
• Design and improve systems built on distributed architectures, APIs, and microservices, with an understanding of failure modes and resilience patterns.
• Make informed engineering trade-offs (e. g., performance vs. maintainability, consistency vs. availability) aligned with business and operational needs.
• Contribute to system and design improvements using modern engineering frameworks, tools, and industry best practices.
• Collaborate with engineers, architects, and technical stakeholders to deliver scalable, reliable, and well-integrated solutions.
• Support technology strategy by evaluating current and emerging technologies in alignment with platform and business goals.
• Create and maintain technical documentation, including system designs, APIs, operational runbooks, and solution specifications.
• Provide production support, lead root cause analysis, and drive long-term fixes rather than short-term patches.
• Mentor team members through technical guidance, design discussions, and knowledge sharing.
• Perform other duties and projects assigned by business management.

Requirements:

• 4-7 years of hands-on software engineering experience in enterprise or telecom environments.
• Strong proficiency in C and C++, with experience in large, long-lived production systems.
• Experience working with Oracle databases and SQL in high-volume, high-reliability systems.
• Solid understanding of distributed systems concepts, including APIs, microservices, concurrency, fault tolerance, and data consistency.
• Demonstrated ability to analyse and diagnose complex technical issues that span multiple systems or components.
• Proven experience working through ambiguity, independently defining problems, assumptions, and solutions.
• Understanding of architectural and operational trade-offs, including latency, throughput, availability, consistency, and maintainability.
• Experience with telecom billing platforms, customer service systems, or related domains (preferred).
• Familiarity with middleware and transaction-based systems such as Tuxedo (preferred).
• Strong analytical, problem-solving, and critical-thinking skills.
• Ability to communicate effectively and collaborate across engineering and technical stakeholder teams.
• Adaptability and resilience in fast-changing, high-impact environments.
• Customer-focused mindset with a commitment to delivering reliable, high-quality solutions.

Must Have Skills:

• Strong C and C++ SW development.
• Strong Oracle Database and SQL, requirements analysis, low-level design, unit test coverage and automation of unit testing.
• GitLab CI, Docker, Kubernetes, AWS.
• Practical use of AI- assisted development tools to improve code quality.
• Productivity and reliability, code review experience.
• Team coaching, team guiding, mentoring.