OverviewIn 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.
ResponsabilitàRun 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




Requisiti fondamentaliHands-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)
Collaborative mindset
Strong written and verbal communication with engineers
Curiosity and meticulous attention to detail
OWASP MASVS/MASTG
Frida
Objection

📌 Mobile Application Senior Security Engineer (Bardi)
🏢 Klarna
📍 Bardi