Infrastructure
Windows and Linux servers, Active Directory, virtualization, backup and monitoring, from single sites to 300+ servers worldwide.
IT Systems Engineer
Denis Hierholzer
Senior Systems Engineer and Lead Network & Security with major IT certifications (CISSP, CEH, LPIC-1, Cisco Certified Specialist) and more than 19 years of experience in Windows and Linux servers, networking, security and automation.
- 19+
- years in IT operations & engineering
- 20
- certifications, incl. CISSP and CEH
- 6
- employers in Germany, Switzerland and the USA
What I do
Reliable infrastructure, secured by design
Network & Security
Cisco ACI, routing and switching, Palo Alto and Check Point firewalls, OT security, micro-segmentation and vulnerability management.
Automation & AI
PowerShell and Python tooling, Ansible, and AI in practice: local and cloud models for coding, RAG and agents.
Currently
Full experience →IT Infrastructure Engineer
Cilag AG – a Johnson & Johnson company · Schaffhausen, Switzerland · since Mar 2021
Engineering and administration of the entire Schaffhausen OT infrastructure (LAN, firewalls, Linux and Windows servers, SAN).