About
Who You're Working With
Penteros is a hands-on offensive security practice — not an agency layer. One senior practitioner scopes, tests, and reports.
Sebastian Sejzer
Ethical Hacker · Infrastructure & Cybersecurity
Penteros is led by Sebastian Sejzer, an ethical hacker with more than 30 years of hands-on experience. That experience spans the full stack an attacker has to move through — so an assessment isn't a scan of one layer, it's a realistic path across all of them.
- System engineering
- Infrastructure
- Cybersecurity
- DevOps & DevSecOps
- Crypto & blockchain
- AI
Experience over certifications. Penteros leads with three decades in real production environments rather than a wall of acronyms. The person who scopes your engagement is the person who tests your systems and writes your report — end to end.
Authorized and accountable. Every engagement runs under a signed NDA and a written authorization / rules-of-engagement document. Penteros is a registered business in Israel (עוסק מורשה).
See How Your System Can Be Breached Before It Happens
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