Lead Offensive Security Engineer: Bug Bounty & Pentest

Klarna; Stockholms kommun; On-site; SEK 900,000 - 1,200,000; Full time

Job summary

Klarna is seeking an experienced Offensive Security professional to join the team in Sweden. You will run penetration tests against internal and public systems, triage Bug Bounty submissions, and analyze findings across the stack.

The role requires writing clear remediation steps and developing Python tooling to automate security processes. You will collaborate with developers, product security, and SOC to drive improvements and ensure secure designs while maturing Klarna's security program.

Qualifications

• 5+ years running penetration tests against production systems.
• Ability to read code and identify real vulnerabilities in Java and Node.js.
• Experience operating in AWS and reviewing microservice architectures for security gaps.
• Clear, actionable remediation steps tied to concrete fixes.
• Ability to script tooling in Python and build secure automation.
• Drive offensive security improvements proactively within Klarna.

Responsibilities

• Run white-box and black-box penetration tests on internal systems and public applications.
• Triage and investigate Bug Bounty submissions and external pentest findings.
• Perform variant analysis to locate related bugs across the codebase and infra.
• Assess security of third-party solutions and integrations.
• Build tooling for reconnaissance, automation, and metrics collection.
• Provide hands-on guidance to developers, product security teams, and SOC.

Skills

Penetration testing

Code review

Python scripting

Java

Node.js

Security reporting

Tools

AWS

Job description

Klarna is seeking an experienced Offensive Security professional to join the team in Sweden. You will run penetration tests against internal and public systems, triage Bug Bounty submissions, and analyze findings across the stack.

The role requires writing clear remediation steps and developing Python tooling to automate security processes. You will collaborate with developers, product security, and SOC to drive improvements and ensure secure designs while maturing Klarna's security program.