Senior Offensive Security Engineer - Penetration Tester

Location: Stockholm

What you will do As a Senior Offensive Security Engineer at Klarna, you will be at the forefront of safeguarding our digital infrastructure and customer data. This position demands a blend of hacking skills, creativity, and a deep understanding of cyber threats. You will simulate sophisticated cyber attacks to identify vulnerabilities, ensuring Klarna's resilience against real-world threats.
• Conduct white-box and black-box penetration testing against internal and public-facing applications and assets.
• Manage, triage, and investigate Bug Bounty submissions and external pentest findings.
• Perform variant analysis on issues discovered through all channels.
• Research and perform security analyses on Klarna's 3rd-party solutions.
• Develop tooling to support reconnaissance, automation, and metrics collection.
• Provide expert guidance to developers, product security teams, and SOC investigations.
• Spread awareness of offensive security practices via demos, workshops, and training.
• Assess the security of our tech stack and help mature Klarna's security program. Who you are
• Strong experience with penetration testing and technical security assessments.
• Experience identifying security issues in code, particularly within Java and Node.js.
• Experience with cloud environments, especially AWS and modern microservice design.
• Comfortable communicating findings clearly with concrete remediation recommendations.
• Skilled in Python scripting and automation.
• Self-driven, proactive, and engaged in advancing Klarna's security culture.
• Industry-recognized certifications (e.g., OSCP, OSWE, CREST, GIAC, AWS).
• Active participation in CTFs and cybersecurity communities. Awesome to have
• Collaboration within a diverse and innovative global team.
• Opportunity to work in Milan with a multicultural environment.
• Challenging scope with exposure to cutting-edge technologies. Please include a CV in English. Curious to learn more about Klarna and what it's like to work here? Explore our career site!"