John S.
Senior Application Security Analyst
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John S. is a dedicated Application Security Analyst with over six years of experience and a remarkable ability to identify and mitigate critical vulnerabilities. With a strong foundation in web application security, John has successfully reduced risk exposure in production environments by up to 85%. His expertise is well-reflected in his proficiency with Java, C++, Python, as well as tools like Burp Suite and OWASP ZAP. Currently working at Intigriti as a freelance analyst, he conducts in-depth vulnerability assessments and security evaluations. Previously, John served as a Software Engineer at Ubuntu Tech Afrika and has developed secure APIs using Spring Boot and Angular. An avid participant in bug bounty programs and CTFs, he continuously hones his skills in ethical hacking. John holds an MSc in Computer Science from the University of Szeged and various cybersecurity certifications, including the Certified Network Security Specialist from ICSI, UK.
Experience
Software Engineer
Ubuntu Tech Afrika · 2023 — 2025Engineered REST APIs utilizing Spring Boot and Angular with an emphasis on secure coding techniques. Implemented authentication and access controls across several application layers.Application Security Analyst
Intigriti · 2023 — PresentPerformed thorough vulnerability assessments on web applications and APIs. Provided security reports that included recommendations for development teams. Conducted DAST employing manual tools such as Burp Suite and OWASP ZAP, along with automated methods. Recognized vulnerabilities such as SQLI, XSS, IDOR, and CSRF across different platforms. Composed technical vulnerability reports and proof of concept exploits while collaborating with program owners regarding significant security issues.Ethical Hacker
Lavenir SAS · 2022 — 2022Carried out penetration tests on web applications following customized testing protocols. Discovered attack vectors including injection flaws, session misconfigurations, and logical errors. Created technical documentation and remediation walkthroughs.Penetration Tester
Link Corporation · 2019 — 2021Executed black-box and gray-box assessments on production systems. Conducted static code reviews for web applications and assessed their security posture against the OWASP Top 10. Worked alongside development teams to facilitate timely remediation of vulnerabilities.Senior Web Developer
Real Developers · 2016 — 2018Developed and maintained secure PHP-based applications tailored for e-commerce clients. Oversaw shared hosting infrastructure and implemented application hardening strategies. Provided mentorship to junior developers regarding web security best practices.
Skills & Expertise
Education
- MSc in Computer ScienceUniversity of Szeged · 2023 — 2025
- BSc in Computer ScienceUniversity of Makeni (UNIMAK) · 2017 — 2022