Job-ID: a6649d a-b5bf- df2fLocation: London; Milan; Stockholm; WarsawSalary: 91196 - GBPType: Full timePosted: Contact: , briefly At Klarna, were building an everyday finance network, helping over 120 million consumers across 26 countries save time and money, and worry less about their finances. Working here means taking on problems most companies never get to solve, and being hands-on enough that the interesting part of the work lands with you, not someone else — youll build with AI, not watch it happen. This is the stretch zone. Come find out what youre capable of. About the role Every payment, login, and stored card in Klarnas iOS and Android apps depends on mobile-specific protections holding up — sandboxing, permission models, anti-tampering — and someone has to attack them before someone else does. Thats you. Youll work as an offensive security specialist focused entirely on Klarnas mobile surface. Youll run penetration tests and red-team exercises against the apps, reverse-engineer builds to find what static review misses, and use the OWASP Mobile Application Security Verification Standard (MASVS) and Testing Guide (MASTG) as your working framework rather than a checklist you fill in after the fact. Youll work closely with the engineering teams who build and harden the apps, turning what you find into fixes that ship, not just findings that sit in a report. What youll do Youll run offensive security assessments — penetration tests, red-team exercises, and vulnerability research — against Klarnas iOS and Android apps. Youll reverse-engineer app binaries to surface sandboxing, permission, and platform-security weaknesses before an outside attacker finds them. Youll test Klarnas mobile apps against the OWASP MASVS and MASTG, and use the results to drive concrete fixes with engineering teams.



Youll evaluate and stress-test app-hardening and RASP protections, working directly with the teams that build and maintain them. Youll write up what you find in a way engineers can act on immediately, and follow through until its actually fixed. Who you are Youve done hands-on offensive mobile security work — professional pentesting, red teaming, bug bounty, or dedicated security research — against iOS, Android, or both. You understand mobile internals: app sandboxing, permission models, and the security architectures of iOS and Android. Youre fluent with mobile security tooling such as Frida, Objection, MobSF, jadx or apktool, Ghidra or Hopper, Burp Suite, and mitmproxy. You work from the OWASP MASVS and MASTG as your reference framework, not as an afterthought. Premio points for Experience securing fintech, payments, or banking apps. Exposure to app-hardening and RASP solutions, from both the attackers and defenders side. Published CVEs, research, conference talks, or a track record in mobile bug bounty programs. Experience shipping production mobile code or similar. Familiarity with mobile app attestation (Play Integrity, App Attest) and device-binding schemes. Things you should know before applying Working together: we value co-located teams; most teams currently meet in the office 2–3 days per week, and this varies by team and can change over time. Non-obvious backgrounds are welcome. Diversity of skills, perspectives and backgrounds is how we create, innovate, and disrupt like no other. Final compensation will be based on the candidates qualifications, skills, and experience. Please include a CV in English. Concrete beats comprehensive — what you built, what it did, what it cost. Curious to learn more about Klarna and what its like to work here? Explore our career site!

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