Author of several add-ons to the Nagios ecosystem. (also Icinga and Naemon)
Implemented monitoring infrastructure for major (>10000 employees) companies.
Refactoring and redesign of messed up monitoring installations. (You know, those which were set up a decade ago, where every two years the responsible admin quits, which nobody dares to touch). I migrate these installations to the OMD (open monitoring distribution) platform which guarantees the stability necessary for effortless operations.
What i also like to do: implement the automatic and unattended generation of configuration files with the tool coshsh. All in all, i migrate unmaintainable and fragmented environments to a consistent and simple out-of-the-box monitoring.
For several customers i designed a monitoring landscape which spans over europe-wide or even global sites. Using the Thruk GUI i merged all the monitored objects into one single view.
Other technologies used in my projects: Grafana for the dashboards, PNP4Nagios (RRD) and InfluxDB for long-term storage of the metrics, Mod-Gearman for load distribution, Prometheus when it comes to cloud-native applications.
Scripting in Perl or Python is part of my daily business. Distributing configs and software with Ansible, too.