System administrator with a love for robust, clean infrastructure

Linux & Windows Server • Docker & CI/CD • Networking • Monitoring

Projects & Experience Short Profile
Portrait of Johannes Krüger

About

People & machines—both should run well.

I am xx years old, from Eberswalde, and I work in Berlin as an IT system administrator. My journey began on 12/08/2013 with my first SSH session and a healthy dose of curiosity: TeamSpeak³ administration, query automation, and later Minecraft networks with Bungeecord and self-hosted cloud setups. What started as tinkering is now daily practice: reproducible, clean infrastructure.

Since 2018, my focus has been on Windows and Linux servers, container orchestration, networking, and monitoring. I think in systems: How do we scale? How do we debug quickly when things break? How do we document so that “future me” says thanks? At Netstack GmbH I build customer-facing solutions—from classic SMB setups to hotel IT with TV systems and CCTV. Different worlds, same principles: stability, transparency, security-by-default.

Away from the rack, I like to build small tools, write reusable snippets, and sweat UI details—as long as they don’t make anything harder. Tech can look nice, but it should never get in the way.

Links

Focus areas

  • System planning
  • Web & DNS
  • Mail admin
  • CI/CD
  • Monitoring

Current topics

  • Observability
  • Security hardening
  • Self-hosted services
  • Automation

Experience

Stable, traceable, documented.

System Administrator

October 2023 – present

Netstack GmbH

At Netstack I support small and medium-sized businesses as well as hotels end to end. I design and operate Windows and Linux server landscapes, automate recurring tasks with CI/CD pipelines, and build transparent monitoring with clear alerts. In the hotel environment I also run TV systems and video surveillance.

netstack.de

Freelance System Administrator

January 2019 – August 2023

sysLUL

As a freelancer I delivered end-to-end solutions—from design and deployment to ongoing operations. This included hardening and operating Linux and Windows servers, providing web and mail services, DNS and domain management, and container deployments with Docker (single-host and Swarm). I handled support remotely and on-site, escalated third-party issues in a structured way, and kept documentation and backups as non-negotiable parts of every project.

Nursing Assistant

November 2020 – September 2023

GLG Martin-Gropius-Krankenhaus GmbH

Working in psychiatry—from a secured ward to the acute unit—taught me to act calmly and methodically under pressure. Clear communication, reliable teamwork and consistent follow-through were part of daily life and are valuable foundations for my IT work today: setting priorities, solving problems pragmatically, and bringing people along.

glg-gesundheit.de

Contact

Brief, direct, constructive.

me@johanneskr.de

(+49) 3334 4299583