Senior Security Engineer

x15ventures operates in the space between corporate and startup. We help build and scale digital ventures, giving teams the freedom to move quickly while maintaining the security, safety and resilience expected of businesses connected to CommBank.

We work across x15 and its portfolio of ventures, partnering with product and engineering teams to understand their risks and build practical security controls into their technology and ways of working.

Where do you fit?

As a Senior Security Engineer, you will help design, build and improve security capabilities across x15 and its ventures.

This is a hands-on engineering role with a strong focus on DevSecOps, cloud security, identity and automation. You will work closely with software engineers, platform teams and venture leaders to embed security into delivery pipelines, cloud environments and day-to-day engineering practices.

You will also mentor other engineers, contribute to technical standards and help lift security capability across the broader x15 community.

In this role, you will

DevSecOps and secure delivery

• Design and implement security capabilities within CI/CD pipelines, including code, dependency, secrets, container and infrastructure-as-code scanning.
• Help teams interpret security findings, prioritise material issues and remediate vulnerabilities without creating unnecessary delivery friction.
• Develop reusable pipeline components, guardrails and secure engineering patterns that can be adopted across multiple ventures.
• Implement policy-as-code and automated compliance checks where these provide a practical and reliable alternative to manual review.
• Contribute to secure coding practices, threat modelling and technical security reviews for new products, services and material changes.
• Design, implement and improve security controls across AWS and Azure environments.
• Review cloud architectures and configurations, identifying risks relating to identity, networking, data protection, logging, workload security and resilience.
• Help ventures implement secure cloud foundations and preventative guardrails using infrastructure as code and native cloud capabilities.
• Work with engineering teams to secure containers, serverless workloads, APIs, data platforms and other cloud-native services.
• Support the implementation and tuning of capabilities such as AWS CloudTrail, GuardDuty, Security Hub, Config and Azure Policy, Defender for Cloud and related services.

Identity and Microsoft security

• Help design and improve identity and access controls using Microsoft Entra ID and associated identity governance capabilities.
• Implement and review controls including Conditional Access, Privileged Identity Management, access reviews, workload identities, application registrations and enterprise application permissions.
• Configure, integrate and improve capabilities across the Microsoft Defender suite, including Defender XDR, Defender for Endpoint, Defender for Identity, Defender for Office 365 and Defender for Cloud.
• Investigate security alerts and work with relevant teams to improve detection quality, coverage and automated response.

Automation and security operations

• Build automation that reduces repetitive security work and enables the small Security team to operate effectively across multiple ventures.
• Develop scripts, integrations and workflows using languages and tools such as Python, PowerShell, APIs, serverless functions and workflow automation platforms.
• Automate security monitoring, evidence collection, vulnerability management, control validation and response activities where appropriate.
• Contribute to detection engineering, security monitoring and incident response across cloud, identity, endpoint and application environments.
• Support the investigation of security incidents and help identify root causes and longer-term control improvements.

Advisory and venture partnership

• Provide practical security advice to venture product, engineering and leadership teams.
• Recommend proportionate controls that consider the nature of the risk, venture maturity, customer experience and delivery constraints.
• Conduct technical security assessments and support ventures to develop prioritised remediation plans.
• Constructively challenge designs or decisions where material security risks have not been adequately addressed.
• Work with CommBank security and technology teams where ventures rely on Group platforms, services or security capabilities.

Technical leadership and mentoring

• Mentor security engineers and other technical team members through pairing, design reviews, technical discussions and constructive feedback.
• Help software and platform engineers build their security knowledge and take greater ownership of security within their teams.
• Contribute to security engineering standards, patterns, playbooks and technical roadmaps.
• Model strong engineering practices, including testing, documentation, peer review, observability and maintainable design.
• Contribute to a collaborative team environment where people are comfortable asking questions, challenging assumptions and learning from mistakes.

We are interested in hearing from people who have

• Strong hands-on experience in security engineering, cloud security, DevSecOps or a closely related discipline.
• Experience designing and implementing security controls within modern software delivery pipelines.
• Strong cloud security experience across AWS and Azure, with deep technical capability in at least one of these platforms.
• Practical experience securing cloud identity and access management, networking, workloads, data, logging and monitoring.
• Experience using infrastructure-as-code technologies such as Terraform, CloudFormation or Bicep.
• Experience with CI/CD platforms such as GitHub Actions, Azure DevOps, GitLab CI or similar technologies.
• Experience implementing security testing within delivery pipelines, such as static analysis, software composition analysis, secrets scanning, container scanning and infrastructure-as-code scanning.
• Practical knowledge of Microsoft Entra ID, including Conditional Access, privileged access, workload identities and application integrations.
• Experience with Microsoft Defender products, particularly Defender XDR, Defender for Endpoint or Defender for Cloud.
• Strong automation and scripting capability using Python, PowerShell or another suitable language.
• The ability to review technical designs, identify material security risks and propose realistic solutions.
• Experience supporting vulnerability management, security monitoring or incident response activities.
• Strong written and verbal communication skills, including the ability to explain technical issues clearly to both engineering and non-technical audiences.
• Experience mentoring engineers and supporting the technical development of others.
• The ability to work independently, manage competing priorities and operate effectively in a small team supporting several businesses.
• A practical mindset and the judgement to distinguish between controls that materially reduce risk and controls that primarily add process.

Useful, but not essential

• Experience with Microsoft Sentinel, security orchestration and automated response.
• Experience building custom detections using Kusto Query Language or similar query languages.
• Experience with cloud security posture management, cloud workload protection or application security posture management platforms.
• Experience securing Kubernetes, container platforms, serverless applications and API-based architectures.
• Familiarity with identity protocols such as OAuth 2.0, OpenID Connect and SAML.
• Experience with GitHub Advanced Security, Microsoft Defender for DevOps or similar developer security tooling.
• Knowledge of secure software development frameworks and standards such as the NIST Secure Software Development Framework, OWASP and the ACSC Information Security Manual.
• Familiarity with the ACSC Essential Eight, NIST Cybersecurity Framework or other commonly used security frameworks.
• Experience working in financial services, fintech, regulated technology environments or businesses handling sensitive customer information.
• Experience working in startup, scale-up or product-led environments where controls need to be proportionate and adaptable.
• Relevant cloud or security certifications. Practical experience and demonstrated technical judgement are more important than certifications alone.

What success looks like

• Security controls are embedded into engineering workflows rather than relying primarily on manual reviews.
• Venture teams receive clear, timely and practical security advice.
• Material cloud and identity risks are identified early and addressed before they become incidents.
• Security findings are prioritised based on risk, with clear ownership and realistic remediation plans.
• Repetitive security activities are automated, allowing the Security team to focus on higher-value work.
• Security tooling generates useful, actionable information rather than unnecessary noise.
• Common security problems are addressed through reusable engineering patterns and guardrails.
• Engineers across x15 have greater confidence and capability in making secure technical decisions.
• Other engineers seek out this role for technical guidance, mentoring and constructive challenge.

You will work across a diverse portfolio of digital ventures, technologies and cloud environments rather than being limited to a single product or platform.

You will have the opportunity to build security capabilities, influence how products are engineered and see the outcomes of your work in practice.

You will also be part of a small Security team where you can make a visible contribution, learn across different security disciplines and help shape how security engineering operates as x15 and its ventures continue to evolve.