System Administrator (f/m/d) - Defense Products

at subsidary IONOS SE in Work from home
Full-time | Permanent | Professionals
Reference ID: I-251


About us

IONOS is the leading European digitalization partner for small and medium-sized businesses (SMB). The company serves around six million customers and operates across 18 markets in Europe and North America, with its services being accessible worldwide. With its Web Presence & Productivity portfolio, IONOS acts as a 'one-stop shop' for all digitalization needs: from domains and web hosting to classic website builders and do-it-yourself solutions, from e-commerce to online marketing tools. In addition, the company offers Cloud Solutions to enterprises who are looking to move to the cloud as their businesses evolve.   


Our team of highly motivated experts against cyber security attacks are looking for more teammates. As a system administrator you will plan and operate together with site reliability engineers and network engineers our defense platforms which protect our hosting products and infrastructure. Besides the classical DDoS Mitigation, we are also responsible for modern web application firewalls, zero trust strategies or content delivery networks (cdn). In a culture which places great value on creative ideas, agile working methods, initiative, and participation you can expect the following tasks.

  • Administration and troubleshooting of highly available and complex infrastructures including participation in an on-call service rotation.
  • Further development and optimization of the distributed DDoS defense platforms as well as the analysis and visualization mechanisms.
  • Monitoring of the systems, analysis of attacks, and observation of current trends.
  • Evaluation and assessment of new technologies and products.
  • Development and implementation of new functions as well as planning and operation of international setups.
  • Support company goals through efficient operating architecture, active lifecycle management, and lean processes in an agile DevOps environment.
  • Conception, setup, and further development of CI/CD pipelines and the necessary technical processes.


You have studied Computer Science or have completed comparable education. You have a keen interest in security topics, good network knowledge, and have the following qualifications.

  • Several years of experience in the administration of complex distributed Linux systems.
  • Configuration and operation of Apache and Nginx as reverse proxy or web application firewall.
  • Deployment of BGP, flowspec, and anycast routing on Linux systems and network routers.
  • A preference to automate with Ansible, Puppet, and Python instead of doing the same manual tasks over and over again.
  • Good analytical skills to evaluate DDoS attacks, implement countermeasures, and continuously develop our defense platforms.
  • First experience with technologies like Docker, Kubernetes or ELK-Stack are beneficial.
  • Like us, you are a fan of Open Source, especially Linux.
  • The ability to communicate with an international team fluently in English, German is a plus.


  • Hybrid working model with home office option.
  • Flexible working hours through trust-based working hours.
  • At some locations a subsidized canteen and various free drinks.
  • Modern office space with very good transport connections.
  • Various employee discounts for activities and products.
  • Employee events such as summer and winter parties, as well as workshops.
  • Numerous training and development opportunities.
  • Various health offers, such as sports and health courses.

apply online now

We value diversity and welcome all applications - regardless of, for example, gender, nationality, ethnic or social origin, religion, disability, age as well as sexual orientation and identity, physical characteristics, marital status or any other irrelevant factor subject to applicable law.


Recruiting Team IONOS

Hinterm Hauptbahnhof 3-5
D-76137 Karlsruhe