Offensive Security Engineer I

Build with us

Businesses deserve better from finance. Less friction, more freedom. Since 2004, Mollie has been on a mission to make payments and money management effortless for every business in Europe.

Today, more than 250,000 companies trust our all-in-one platform to get paid, manage money and grow on their terms. Simple, scalable and built with real businesses in mind.

We’re one of Europe’s fastest-growing fintechs, with 900+ Mollies across 12+ locations. Our people make this growth possible. We move fast, build with purpose and care deeply about our customers. Whether you’re solving problems, building market-leading products or exploring how AI can make work smarter, you’ll have the freedom to create and the trust to deliver.

If you’re ready to grow, shape the future of fintech and join an ambitious, high-performing team, this is the place for you.

Your impact

As an Offensive Security Engineer, you help protect Mollie’s platform and the businesses that depend on it by thinking like an attacker—then working like a partner.

You’ll proactively identify and validate vulnerabilities across our products and infrastructure, and collaborate closely with Product Engineering, Security Engineering, and Security Operations to drive issues from discovery all the way through fix verification and closure. Your work helps us ship quickly without compromising on security, resilience, or customer trust.

What you’ll ship

• Penetration testing that matters: Plan and execute security assessments across web applications, APIs, cloud services, and internal systems—focused on realistic attack paths and business impact.

• Vulnerability validation & prioritisation: Confirm exploitability, reduce false positives, and help teams understand severity and remediation options.

• Attack simulations: Partner with SecOps and Security Engineering to run collaborative exercises (e.g., detection validation, incident simulations, phishing/crisis scenarios) that strengthen real-world readiness.

• Offensive methodology & tooling: Improve playbooks, testing approaches, and automation to scale offensive security across teams and technologies.

• Security through collaboration & awareness: Partner closely with engineering teams to answer questions, support fixes, retest, and uplift secure development practices—while also contributing to security awareness initiatives across the organization.

What you’ll bring

• 2+ years of hands-on offensive security experience (penetration testing, ethical hacking, product security engineering)

• Certifications such as OSCP, OSCE, or similar are highly preferred.

• Practical experience testing modern web applications and APIs (auth, authorization, business logic, data handling)

• Familiarity with common testing tools and techniques (e.g., Burp Suite and similar tooling)

• Basic scripting/automation skills (Python, Bash, or similar) to speed up repeatable work

• Understanding of cloud environments and common attack vectors (GCP concepts are all welcome)

• Ability to write clear, actionable findings and communicate risk to both technical and non-technical stakeholders

• A collaborative mindset: you enjoy partnering with teams to get issues fixed and verified

Grow your way

At Mollie, growth is personal. We believe everyone should have the chance to develop their skills, explore new challenges and shape their career on their own terms.

You’ll get regular feedback and performance reviews to support your development, with fair and transparent salary reviews along the way. Many Mollies move into new roles or take on new projects to stretch themselves, and we actively hire from within to help you take the next step.

No matter if you’re aiming for promotion, exploring a different career path or building new skills, you’ll be supported with the tools, trust and opportunities to grow your way.

Unlock your full potential and join us to eliminate financial bureaucracy

If you’re excited by the idea of building what’s next, for yourself and for thousands of businesses across Europe, we’d love to hear from you. Apply with your CV (in English) using the form below.

Want a peek behind the scenes? Check out what life at Mollie is really like.