10 hours ago
London, United KingdomSenior
Responsibilities
- Run white-box and black-box penetration tests against internal systems and public-facing applications.
- Manage, triage, and investigate Bug Bounty submissions and external penetration-test findings.
- Perform variant analysis to identify related vulnerabilities across the codebase and infrastructure.
- Assess the security of third-party solutions and integrations.
- Build tooling for reconnaissance, automation, and metrics collection.
- Provide hands-on security guidance to developers, product security teams, and SOC investigations.
- Run demonstrations, workshops, and training on offensive security practices.
- Assess Klarna’s technology stack and help mature the broader security program.
Requirements
- At least 5 years of experience running penetration tests and technical security assessments against production systems.
- Ability to read code and identify vulnerabilities, particularly in Java and Node.js.
- Comfort operating in AWS and reviewing microservice architectures for security gaps.
- Ability to document findings clearly and provide concrete remediation steps.
- Ability to script security tooling in Python.
- Bonus: OSCP, OSWE, CREST, GIAC, or AWS security certification.
- Bonus: active participation in CTFs or the security research community.
- Bonus: public security research such as CVEs, conference talks, or published tooling.
Benefits
- Based in Klarna’s Milan office with most teams meeting in person 2–3 days per week; this varies by team and may change over time.
- Non-obvious backgrounds and diverse skills, perspectives, and backgrounds are welcomed.
About Klarna
Klarna is a privately held fintech that provides buy now, pay later financing, checkout, and a consumer shopping app for e-commerce and retail. It monetizes through merchant fees, interchange, and interest and fees on financing, while offering marketing and customer acquisition tools to merchants. Founded in 2005 and headquartered in Stockholm, it operates across Europe and North America.