Stamatis S.

I'm a Senior Android Developer and Application Security Engineer with 7+ years of experience building, analyzing, and securing mobile applications. My background combines hands-on Android development with offensive application security. I can work inside an application's architecture and source code as a developer, then approach the same application from an attacker's perspective to identify vulnerabilities and weaknesses. Android Development I develop and maintain Android applications using modern technologies and architecture, including: • Kotlin & Java • Jetpack Compose • Android SDK • Modern Android architecture • REST APIs and backend integration • Authentication and authorization • Performance optimization • Debugging and troubleshooting • Application modernization and refactoring • Secure mobile application development Whether you need a new Android application, help with an existing codebase, architectural improvements, bug fixing, or an experienced developer to take ownership of a complex project, I can work across the full Android development lifecycle. Mobile & Web Application Security I also perform security assessments and penetration testing for mobile and web applications. My services include: • Android application penetration testing • Mobile application security assessments • Web application penetration testing • Authentication and authorization testing • API security testing • Static and dynamic application analysis • Secure code review • Insecure data storage and local security testing • Network security testing • Input validation and common vulnerability testing • Vulnerability analysis and reporting • Practical remediation guidance For mobile security assessments, I work with industry-standard methodologies and tools, including OWASP MASVS/MASTG, Burp Suite, Frida, JADX, MobSF, OWASP ZAP, and other static and dynamic analysis tools. Security Engineering & Automation Beyond manual penetration testing, I have experience integrating security practices and tooling into the software development lifecycle. This includes areas such as: • SAST and secure code analysis • Software composition analysis and dependency security • Secret detection • CI/CD security automation • CodeQL • Gitleaks • Trivy • SonarCloud and security-focused code analysis My development background means that I don't simply identify vulnerabilities and hand over a generic report. I understand how applications are built, how vulnerabilities are introduced at the code and architectural level, and what practical remediation looks like for developers. Why work with me? You get someone who can understand your application from both sides. As a developer, I understand architecture, source code, APIs, authentication flows, mobile platforms, and the practical constraints of building software. As a security engineer and penetration tester, I analyze those same systems from an attacker's perspective. Whether you need an experienced Android developer, a security assessment of your mobile or web application, or someone who can help bridge the gap between development and application security, I can help.