Senior Security Specialist.

Your expertise, your direction

At DEFION, we work mostly with short projects of one to two weeks. That means you will work with many different organizations and application types in rapid succession. Some weeks it is a cloud environment, the next it is Active Directory, then a mobile app. Variety is built into the role.

But beyond that, you shape this position yourself. Want to go deep on red teaming? Become a tech lead? Develop tooling? Train juniors? Advise clients on security strategy? We create the role that fits your strengths and ambitions.

What you will do

• Conduct a full range of offensive security tests: web applications, infrastructure, cloud, mobile, and more
• Document findings in detailed reports and present results directly to clients
• Specialize in areas that match your interests: cloud security, red teaming, infrastructure, or security consulting/governance
• Provide security training, advise prospects, and mentor juniors and interns
• Develop and improve internal tooling when that is where your passion lies

What you bring

Must have:

• Proven experience with pentesting and security assessments
• Broad IT knowledge: programming, networking, databases, Linux internals
• Knowledge of Cloud Security (AWS/Azure), Active Directory, mobile app security, OAuth/SAML, cryptography
• Experience with tools like Burp Suite, Nessus, or Nmap
• Strong knowledge of common vulnerabilities (XSS, CSRF, SQLi) and how to mitigate them
• A bachelor's or master's degree in a technical field (HBO/WO level)
• Ability to communicate technical findings clearly, both verbally and in writing

Nice to have:

• Published CVEs to your name
• Experience in security consulting or governance advisory