# Penetration Tester

Locale: `en`

Source: `/en/careers/penetration-tester/`

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1. [Overview](/en/careers/penetration-tester/#topic-overview)

STH Careers

Full-time (Hybrid)
              Operational (Junior and Mid-level)

# Penetration Tester

Join the offensive security team assessing web, mobile, and API systems for enterprise clients.

![Illustration of an ethical hacker testing web and mobile applications](/assets/generated/careers/role-pentester.webp)

Conduct manual penetration testing and source code reviews to identify vulnerabilities across web applications, mobile apps, and APIs for leading organizations under recognized standards.

## Key Responsibilities

- Perform authorized penetration testing on web applications, mobile apps (iOS and Android), and API endpoints.
- Conduct secure code reviews to discover logic and implementation flaws.
- Continuously research emerging security vulnerabilities and best-practice mitigations to advise clients.
- Produce comprehensive technical penetration test reports in English.

## Qualifications and Skills

- At least 1 year of hands-on penetration testing experience.
- Proficiency in Linux, Burp Suite, and at least one programming language (Python, Go, Bash, JavaScript, or PHP).
- Solid understanding of OWASP Top 10 principles for web or mobile systems.
- Passionate about offensive security, ethical hacking, and continuous technical growth.
- Good written English skills for technical report authoring (e.g. TOEIC score 500+ or equivalent).
- Possess at least one recognized security certification (OSCP, BSCP, PenTest+, or equivalent).
- Prior participation in competitive programming or CTF challenges (ACM ICPC, Olympiad in Informatics, Thailand Cyber Top Talent) is an advantage.

## Growth Opportunities

- Hands-on exposure to diverse scopes including fintech, e-KYC, and mission-critical cloud infrastructure.
- Full exam sponsorship for advanced offensive security certifications.
- Opportunity to participate in vulnerability research covering firmware, drivers, and binary exploitation.

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Last updated 13 October 2026