In this role you will lead offensive security testing for Klarna’s mobile apps, focusing on iOS and Android; you’ll work with engineering teams to turn findings into fixes and improve app hardening. You’ll apply MASVS/MASTG guidelines to drive concrete security improvements, not just produce reports. The role combines hands‑on testing, reverse engineering, and collaboration to reduce risk in a fintech mobile ecosystem. This is a hands‑on position in a fast-moving security team with real impact on product security.
Run offensive security assessments (penetration tests, red-team exercises, vulnerability discovery) on Klarna’s mobile apps (iOS/Android)
Reverse‑engineer app binaries to uncover sandboxing, permission, and core security weaknesses
Test against OWASP MASVS/MASTG and translate results into actionable fixes with engineering teams
Evaluate and stress‑test app‑hardening and RASP protections
Document findings in actionable formats and ensure fixes are implemented in production
Hands‑on offensive mobile security experience (pentesting,



red teaming, bug bounty, or security research) against iOS/Android
Strong understanding of mobile internals: sandboxing, permissions, security architectures of iOS and Android
Fluent with mobile security tooling (Frida, Objection, MobSF, jadx/apktool, Ghidra/Hopper, Burp Suite, mitmproxy)
Familiarity with OWASP MASVS/MASTG as primary framework for security assessments
Experience with app‑hardening and RASP; fintech/payments app security a plus
Published CVEs, talks, or track record in mobile security or bug bounty (premio)
Experience shipping production mobile code or similar
Familiarity with Play Integrity/App Attest and device‑binding schemes (bonus)
Strong written and verbal communication with engineers
Curiosity and meticulous attention to detail
OWASP MASVS/MASTG
Frida
Objection
Mobile Application Senior Security Engineer pavia, lombardia, it
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📌 Mobile Application Senior Security Engineer (Bardi)
🏢 Klarna
📍 Bardi