Senior Security Engineer - Crypto

Stack Recruitment; Fatih; On-site; TRY 360,000 - 540,000; Full time

Benefits offered by this job

Research time for tooling and security

Career growth in technical security

Job summary

Stack Recruitment is seeking a Senior Application Security & Penetration Testing Engineer to join a fast-growing global cybersecurity company focused on web and mobile security.

You will lead offensive security assessments across web, mobile, cloud, and API environments, produce clear reports, and contribute to tooling development and community initiatives while working with clients to improve security at scale.

Qualifications

• 4+ years of application security and penetration testing.
• Strong experience with web application and API security.
• Experience testing mobile applications (Android and/or iOS).
• Familiarity with cloud platforms and security risks (AWS, Azure, GCP).
• Experience with scripting languages such as Python and/or Bash.
• Solid understanding of cryptography fundamentals.
• Excellent analytical and problem‑solving abilities.
• Strong written and verbal communication skills.
• Bachelor’s degree in Computer Science, Information Security, or a related field.

Responsibilities

• Conduct external and internal network penetration tests.
• Identify complex vulnerabilities including logic flaws, authentication issues, and privilege escalation paths.
• Conduct cloud security reviews across AWS, Azure, and/or GCP.
• Assess IAM configurations, access controls, and misconfiguration risks.
• Understand how application and cloud security intersect in modern environments.
• Produce clear, high‑quality pentest reports for technical and non‑technical audiences.
• Communicate risk, impact, and remediation guidance effectively.
• Work closely with clients to support security improvements.
• Research and develop new penetration testing techniques and tools.
• Contribute to internal R&D efforts and community knowledge sharing.

Skills

Application security

Penetration testing

Web security

API security

Mobile security testing

Cloud security

Python

Bash

Cryptography fundamentals

Education

Bachelor's degree in Computer Science or Information Security

Tools

AWS

Azure

GCP

Job description

Senior Application Security & Penetration Testing Engineer – Web & Mobile Security

About the Company

A fast‑growing global cybersecurity company is building advanced security capabilities at the intersection of application security and blockchain technology. The company delivers security services across web, mobile, cloud, and modern application environments, supporting clients operating mission‑critical systems worldwide.

By combining deep technical expertise with ongoing research and tooling development, the organisation delivers high‑impact security assessments, penetration testing, and security reviews for complex, real‑world platforms. It is strongly committed to security excellence, transparency, and continuous innovation.

This opportunity is ideal for a hands‑on senior application security professional with strong penetration testing experience across web and mobile applications.

The role is highly technical and delivery‑focused, offering exposure to a wide range of systems including modern APIs, cloud infrastructure, and emerging Web3 environments. The successful candidate will work directly on security assessments while also contributing to research, tooling, and community initiatives.

This is a high‑impact role requiring strong offensive security skills, clear communication, and a passion for improving application security at scale.

Key Responsibilities

• Conduct external and internal network penetration tests.
• Identify complex vulnerabilities including logic flaws, authentication issues, and privilege escalation paths.
• Conduct cloud security reviews across AWS, Azure, and/or GCP.
• Assess IAM configurations, access controls, and misconfiguration risks.
• Understand how application and cloud security intersect in modern environments.
• Produce clear, high‑quality pentest reports for both technical and non‑technical audiences.
• Communicate risk, impact, and remediation guidance effectively.
• Work closely with clients to support security improvements.
• Research and develop new penetration testing techniques and tools.
• Contribute to internal R&D efforts and community knowledge sharing through blogs, tools, or presentations.

Qualifications

• 4+ years’ experience in application security and penetration testing.
• Strong experience with web application and API security.
• Experience testing mobile applications (Android and/or iOS).
• Familiarity with cloud platforms and security risks (AWS, Azure, GCP).
• Experience with scripting languages such as Python and/or Bash.
• Solid understanding of cryptography fundamentals.
• Excellent analytical and problem‑solving abilities.
• Strong written and verbal communication skills.
• Bachelor’s degree in Computer Science, Information Security, or a related field.

Bonus Experience

• Experience testing Web3 or blockchain‑based applications.
• Exposure to smart contract security audits.
• Participation in bug bounty programs or security audit contests.
• Offensive security certifications (OSCP, OSWE, OSCE, GWAPT, or similar).
• Published security research, blog posts, or conference presentations.

Offer Highlights

• Dedicated time for research and skill development.
• Growth opportunities within a highly technical security environment.