Senior Security Engineer - Mobile Network Security

As an iconic Australian brand with a global footprint, our purpose is to build a connected future where everyone can thrive. We’re committed to delivering the best experiences through the best technology on the best network — and making Telstra the place you want to work. For you, this means a career that grows with you, supported by a team built on genuine human connection that values wellbeing, flexibility, and growth.

What We Offer

• Competitive, performance-based pay
• Access to thousands of learning programs to help you grow your skills
• Purchased annual leave scheme
• An additional Telstra day off each year
• 30% discount on Telstra products and services

Make a Difference

As a Senior Security Engineer in our GNT Business Unit, you’ll apply your expertise in Telecommunications, Mobile Core and RAN technologies, Automation, Infrastructure as Code (IaC), and Cyber Security to strengthen the security of Telstra’s mobile networks. You’ll help design, integrate, and operate security capabilities across our Mobile Core, RAN, and orchestration systems using DevSecOps and Agile practices. This hands-on role will position you as a trusted advisor to cross-functional teams — delivering secure, scalable solutions and safeguarding the confidentiality, integrity, and availability of our network.

What you’ll do

• Define and operationalise security controls across Mobile Core and RAN platforms.
• Embed secure-by-design principles into engineering standards and frameworks.
• Lead the design, integration, and support network technologies and platforms in line with Telstra’s tech strategy.
• Enhance automation and CI/CD practices to improve delivery speed and quality.
• Engage with business and technical stakeholders to deliver practical, customer-focused security solutions.
• Provide technical leadership and mentoring to support team development.
• Evaluate vendor solutions and manage performance to ensure secure outcomes.
• Document work for continuity, knowledge sharing, and operational excellence.
• Participate in the on-call roster to support critical incident response.

What You’ll Bring

• Broad understanding of Mobile Core, Radio Access Networks (RAN), and security engineering across Network, Telco Cloud, and DevSecOps environments.
• Strong technical expertise in TCP/IP routing, RAN, Linux, Docker, and Kubernetes.
• Hands-on experience securing modern infrastructure (e.g. Docker, Kubernetes, IaC with Terraform/CDK).
• Experience delivering security capabilities via automation and CI/CD pipelines.
• Familiarity with Agile methodologies and tools.
• Knowledge of key security standards/frameworks (e.g. SOCI, NIST, GSMA, 3GPP).
• Strong interpersonal skills with the ability to collaborate across teams and partners.

Nice to Have

• Experience with system hardening and best practice implementations.
• Experience deploying security capabilities through automation and CI/CD pipelines.
• Degree in Cyber Security, Cloud Security, Telecommunications, or Network Security — or equivalent industry experience.
• Relevant certifications such as CISSP, CCIE (Security), CompTIA Security+, or Cloud Security certifications (mandatory for cloud security-focused roles).

If you’re passionate about being part of an agile, experienced team and contributing to cutting-edge mobile security, we’d love to hear from you.

At Telstra, we fully embrace flexibility we encourage you to work where, when, and how you are most effective. Talk to us about how this role could flex for you!

We are committed to building a diverse and inclusive workforce. We welcome applicants of all genders, cultures, linguistic backgrounds, and people living with disabilities. To learn more about how we support our people, including accessibility adjustments, visit tel.st/thrive.