Mobile Application Senior Security Engineer
Pubblicato il 02-10-2026 - Klarna in Milano
Job-ID: a6649d a-b5bf- df2fLocation: London; Milan; WarsawSalary: 91196 - GBPType: Full timePosted: Contact: , briefly At Klarna, we're 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 — you'll build with AI, not watch it happen. This is the stretch zone. Come find out what you're capable of.
About the role
Every payment, login, and stored card in Klarna's 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. That's you. You'll work as an offensive security specialist focused entirely on Klarna's mobile surface. You'll 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. You'll 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 you'll do
You'll run offensive security assessments — penetration tests, red-team exercises, and vulnerability research — against Klarna's iOS and Android apps. You'll reverse-engineer app binaries to surface sandboxing, permission, and platform-security weaknesses before an outside attacker finds them. You'll test Klarna's mobile apps against the OWASP MASVS and MASTG, and use the results to drive concrete fixes with engineering teams. You'll evaluate and stress-test app-hardening and RASP protections, working directly with the teams that build and maintain them. You'll write up what you find in a way