10 hours ago
Warsaw, PolandSenior
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.
- Research the security of third-party solutions and integrations.
- Build tooling for reconnaissance, automation, and metrics collection.
- Support developers, product security teams, and SOC investigations with hands-on security expertise.
- Deliver demos, workshops, and training on offensive-security practices.
- Assess Klarna’s technology stack and help mature the overall 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.
- Experience operating in AWS and reviewing microservice architectures for security gaps.
- Ability to produce clear findings with concrete remediation steps.
- Ability to script custom tooling in Python.
- Demonstrated initiative in advancing offensive-security practices.
- Preferred qualifications include OSCP, OSWE, CREST, GIAC, or AWS security certifications; CTF or security-research participation; and public research such as CVEs, conference talks, or published tooling.
Benefits
- The role is based in Klarna’s Milan office.
- Most teams currently meet in person two to three days per week, though this varies by team and may change over time.
- Candidates from non-obvious backgrounds are welcome.
- A CV in English is required.
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.