Security Engineer Cover Letter: Example, Template + How to Write One in Australia

12 October 2025

Ms Catherine Park
Chief Information Security Officer
Commonwealth Bank of Australia
Level 15, Tower 1, 201 Sussex Street
Sydney, NSW 2000

Dear Ms Park,

When I discovered that Commonwealth Bank is seeking a Security Engineer to strengthen security posture across cloud and on-premises infrastructure while leading vulnerability management and incident response initiatives for critical banking systems, I recognized this was precisely the opportunity I’ve been working toward. As someone who served as Security Engineer at SecureNet Solutions—protecting enterprise infrastructure supporting 2,500+ users and processing 12 million daily transactions across financial services clients achieving zero successful breach incidents during 40-month tenure, conducting comprehensive vulnerability assessments and penetration testing across 180+ systems identifying and remediating 850+ vulnerabilities including 45 critical-severity findings reducing overall risk exposure by 73%, implementing security monitoring and SIEM solutions using Splunk and Azure Sentinel that detected and mitigated 320+ security incidents with average response time of 18 minutes achieving 99.2% threat containment rate before lateral movement, architecting secure cloud infrastructure in AWS and Azure including identity and access management, network segmentation, encryption strategies, and compliance controls meeting ISO 27001, PCI-DSS, and APRA CPS 234 requirements, and leading security awareness training programme reaching 1,800+ employees reducing phishing click rates from 31% to 7% and security incidents attributed to human error by 64%—I’m thrilled at the prospect of combining cybersecurity expertise and financial services security knowledge for Australia’s leading banking institution.

Over the past five years as a Security Engineer working throughout Brisbane and Sydney’s financial services and technology sectors, I’ve repeatedly delivered results that match perfectly with your needs. I’ve designed and implemented security architectures for cloud-native and hybrid environments incorporating zero-trust principles, defence-in-depth strategies, and security-by-design methodologies protecting customer data, intellectual property, and critical business systems across AWS, Azure, and Google Cloud Platform, performed regular penetration testing and vulnerability assessments using tools including Burp Suite, Metasploit, Nessus, and Qualys identifying security weaknesses across applications, networks, and infrastructure with comprehensive remediation recommendations prioritised by risk and business impact, managed security operations including log analysis, threat hunting, and security incident investigation using SIEM platforms, EDR solutions, and threat intelligence feeds detecting advanced persistent threats, insider risks, and zero-day exploits with documented incident response procedures and post-incident reviews, implemented and maintained security controls including firewalls, intrusion detection/prevention systems, web application firewalls, DLP solutions, and endpoint protection platforms reducing attack surface and ensuring compliance with regulatory requirements, collaborated with development teams to integrate security into DevSecOps pipelines implementing automated security testing, static/dynamic code analysis, container security scanning, and infrastructure-as-code security validation shifting security left and reducing vulnerabilities in production by 58%, and maintained security documentation including policies, procedures, architecture diagrams, and risk assessments supporting internal audits, external compliance assessments, and executive reporting on security posture and risk landscape. My background spanning security architecture, penetration testing, incident response, and compliance has shown me that exceptional security engineering merges technical depth with business risk understanding—precisely what you require for protecting critical financial infrastructure and customer trust.

What really attracts me to Commonwealth Bank is your commitment to cybersecurity excellence protecting millions of Australian customers and your investment in cutting-edge security technologies and professional development for security teams. I hold CISSP (Certified Information Systems Security Professional), CEH (Certified Ethical Hacker), and OSCP (Offensive Security Certified Professional) certifications through ISC² and Offensive Security, Bachelor of Computer Science (Cybersecurity) from Queensland University of Technology, and completed specialized training in cloud security architecture, threat intelligence analysis, and security operations. I’m proficient with security tools including Splunk, CrowdStrike, Palo Alto Networks, Tenable, and Rapid7, experienced with security frameworks including NIST Cybersecurity Framework, ISO 27001, and CIS Controls, and knowledgeable about regulatory requirements including Privacy Act, Notifiable Data Breaches scheme, and APRA prudential standards. One achievement I’m particularly proud of is leading security architecture redesign for legacy payment processing system handling $45 million daily transaction volume by conducting comprehensive threat modeling identifying 23 potential attack vectors, implementing network microsegmentation with strict access controls, deploying application-layer security controls including input validation and encryption, establishing real-time monitoring with automated alerting, and conducting red team exercise validating security improvements, which achieved 89% reduction in exploitable vulnerabilities, maintained zero unplanned downtime during 8-month implementation, and passed stringent PCI-DSS audit with zero findings earning ‘Security Innovation Award’ and establishing model approach adopted across three additional business units. I’m convinced that Security Engineers aren’t merely firewall administrators implementing security products—we’re risk managers who translate technical threats into business impact, problem solvers who architect secure solutions enabling business innovation, and trusted advisors who balance security requirements with operational efficiency and user experience ensuring organizations can operate safely in increasingly hostile threat landscape.

I’d welcome the chance to discuss how my proven ability to strengthen security posture while managing vulnerabilities and responding to incidents can protect Commonwealth Bank’s critical infrastructure and customer data. Thank you for reviewing my application, and I look forward to connecting with you soon.

Kind regards,

Ryan Torres
[email protected]
0428 567 234
linkedin.com/in/ryantorres-infosec