Complex systems,
made clear.

Native German speaker, equally proficient in technical, professional, and personal contexts, both written and spoken.

Near-native proficiency, used daily in international projects, technical documentation, and cross-functional team communication at Siemens.

Advanced recreational skier on alpine slopes, going out from time to time.

Active diver with experience in varied waters and conditions, including night dives and deep dives. Trained to CMAS standard.

Agile methods such as Scrum and Kanban organise software development and IT operations into short iterations with regular feedback, enabling quick responses to change.

IT consulting covers clarifying requirements, evaluating options, and developing solution concepts for clients and stakeholders, including in complex international environments.

Event management covers the technical planning and coordination of events, from aligning with partners and speakers through the on-site setup to safeguarding the schedule with redundancy and prepared fallback options.

IT support ensures smooth operations for end users, from direct device-level problem resolution to coordinating and escalating complex incidents with vendors and third parties.

Project management covers requirements clarification, stakeholder alignment, scheduling, and owning IT initiatives from concept through to ongoing operations.

SQL is the standard language for relational databases and enables creating, querying, and managing structured data. Databases in use include MariaDB, PostgreSQL, and SQLite.

Technical documentation makes systems understandable for developers, operators, and decision-makers, covering UML diagrams, requirements analyses, operations manuals, and decision papers.

Distributed systems run computations across multiple independent nodes that coordinate together. Key properties are consistency, fault tolerance, and decentralised coordination, as described by the CAP theorem.

High availability describes the ability of systems to remain operational despite partial failures. It is achieved through redundancy, automatic failover, and defined recovery objectives (RTO and RPO).

IT architecture designs the overall structure of systems and system landscapes to meet business requirements, remain scalable, and stay manageable in production.

Microservices architectures decompose applications into small, independently deployable services that communicate via APIs. This enables independent scaling and allows teams to develop and operate individual services separately.

Service design shapes IT services from the user's perspective by capturing requirements, understanding workflows, and deriving practical, accepted solutions from them.

System integration brings hardware, operating systems, and services together into a functioning, documented whole, covering requirements analysis, commissioning, and handover to operations.

App lifecycle management covers submitting, signing, and approving applications in the Google Play Store and Apple App Store, and distributing them to managed devices via MDM platforms.

IT automation replaces manual, recurring processes in administration, deployment, and configuration with scripts and toolchains, ranging from simple Bash routines to fully orchestrated pipelines with Ansible and CI/CD.

Continuous integration and continuous delivery automate build, test, and deployment processes so that code changes can be released reliably and traceably. Used primarily with Gitea Actions.

Backup strategies protect data against loss from hardware failure, attacks, or human error. Borgbackup and Restic are used for deduplicated, encrypted backups to local and offsite destinations.

DevOps bridges software development and IT operations through shared processes, automation, and monitoring, enabling faster and more reliable delivery of software changes.

IT infrastructure forms the technical foundation for all IT services, encompassing networking, servers, storage, virtualisation, and operating systems. Planning, building, and ongoing operations are all part of the discipline.

The Internet of Things connects physical devices and sensors to networks to capture data and trigger actions. Used in personal and community projects with MQTT and Home Assistant.

Configuration management handles server configurations as versioned code, making environments reproducible and changes traceable. The primary tool is Ansible.

Load balancing distributes incoming requests across multiple backend instances to increase availability and throughput. In Linux environments nginx is used as a reverse proxy, or native kernel mechanisms are applied.

Mobile device management enables central management, security, and monitoring of devices across all platforms. In enterprise use, AirWatch and Microsoft Intune are the primary tools.

Multimedia covers setting up and operating audio, video, and presentation technology for events, so content reaches several hundred participants and speakers reliably.

Self-hosting runs services on own or rented infrastructure rather than public cloud platforms, with full control over data, configuration, and updates. Typical services include Nextcloud, Gitea, mail servers, and monitoring stacks.

Telephony and communication infrastructure covers analogue lines, VoIP systems, and mobile device integration, used in home and office environments.

Virtualisation abstracts physical hardware so that multiple virtual machines or containers run independently on the same hardware. Technologies in use include KVM, VMware, and Docker.

IT security covers protecting systems and infrastructure against unauthorised access, data loss, and attacks, with focus areas in network security, cryptography, access management, and secure system design.

The GDPR governs the protection of personal data across the EU. Technical implementation covers selecting GDPR-compliant hosting providers, encrypted storage, and consistent data minimisation.

The Domain Name System translates domain names into IP addresses and is fundamental to how the internet functions. Running own infrastructure adds internal zones, split-DNS, and DNSSEC.

Identity and access management controls who can access which resources. Core concepts include single sign-on (SSO), role-based access control (RBAC), and full identity lifecycle management, implemented with Keycloak.

Cryptography protects data and communication from unauthorised access through mathematical methods. Practically relevant areas include end-to-end encryption, TLS certificates, asymmetric key pairs, and secure key management.

Network security protects IT infrastructure through segmentation, hardening, and continuous verification against unauthorised access and attacks, typically using firewalls, intrusion detection systems, and zero-trust approaches.

A virtual private network encrypts network traffic and securely connects remote locations or devices. The primary protocol is WireGuard, which delivers significantly better performance than older solutions like OpenVPN at the same security level.

Android is Google's open-source mobile operating system based on the Linux kernel, running on billions of devices. In enterprise environments it is managed via MDM platforms, with app distribution through the Google Play Store.

iOS is Apple's mobile operating system for iPhone and iPad. In enterprise contexts the focus is on central management via MDM platforms, signing and distributing corporate apps, and enforcing security policies.

Linux is an open-source Unix-like operating system whose kernel forms the base for countless server, desktop, and embedded systems. In server operations it covers installation, hardening, configuration, and ongoing maintenance.

macOS is Apple's desktop operating system for Mac computers. In enterprise contexts this includes MDM integration through AirWatch or Intune, deployment of corporate apps, and enforcement of security and configuration policies.

Windows Server and Windows Client are Microsoft's operating system platforms for enterprise environments. Operations include installation, configuration via Group Policy, Active Directory integration, and endpoint management.

Amazon Web Services (AWS) is one of the leading public cloud platforms with over 200 services, including EC2 for compute, S3 for object storage, and CloudWatch for monitoring. Used for building the Mobile Workplace project at Siemens.

Docker packages applications and their dependencies into containers that run identically on any system. This enables reproducible, isolated deployments and is the foundation for self-hosting setups and CI/CD pipelines.

Hetzner is a German hosting provider with data centres in Germany and Finland. Their offering ranges from dedicated servers and cloud instances to object storage, at GDPR-compliant prices well below US cloud providers.

KVM (Kernel-based Virtual Machine) is a type-1 hypervisor built into the Linux kernel. It runs complete operating systems as virtual machines with direct hardware access and is the foundation for on-premise private cloud infrastructure.

OpenNebula is an open-source cloud management platform for hybrid infrastructure. It orchestrates KVM VMs and containers on on-premise and edge infrastructure and provides a unified interface for provisioning, networking, and storage.

internet.nl is a testing tool operated by the Dutch government that checks whether domains comply with modern internet standards, including IPv6, DNSSEC, TLS configuration, and email security standards such as DMARC and DKIM.

Keycloak is an open-source identity and access management platform. It provides single sign-on via OpenID Connect and SAML, user federation over LDAP and Active Directory, and fine-grained role and permission management.

Free, automated certificate authority by the Internet Security Research Group, issuing TLS certificates for HTTPS and renewing them automatically via the ACME protocol.

Nginx is a web server and reverse proxy with high throughput and low memory footprint. It is used for TLS termination, load balancing, and as the central entry point in self-hosting setups.

OPNsense is a FreeBSD-based open-source firewall and router distribution. It provides network segmentation, stateful packet inspection, VPN gateways, and intrusion detection through a web-based interface.

TLS (Transport Layer Security) is the standard protocol for encrypting network communication and replaced the now-deprecated SSL. In self-hosted operations this includes issuing, renewing, and managing certificates, typically automated via Let's Encrypt.

UniFi is Ubiquiti's network ecosystem comprising managed switches, Wi-Fi access points, and gateways. The entire infrastructure is centrally administered through the UniFi Network Controller, either locally or as a cloud service.

WireGuard is a modern VPN protocol integrated into the Linux kernel that, through minimal code and modern cryptography, offers significantly simpler configuration and higher performance than OpenVPN or IPsec.

Grafana is an open-source visualisation platform for metrics, logs, and traces. It connects to data sources including InfluxDB, Prometheus, and Amazon CloudWatch and presents data in configurable dashboards with alerting.

InfluxDB is a time series database for metrics, events, and measurements, optimised for high write throughput and time-based queries. Combined with Telegraf as a metrics agent and Grafana for visualisation, it forms a complete monitoring solution.

Monitoring collects metrics, logs, and traces from systems and applications to understand their state and detect problems early. Tools in use include Grafana, InfluxDB, Telegraf, Prometheus, and Amazon CloudWatch.

Prometheus is an open-source monitoring system that pulls metrics from services and stores them in a time series database. PromQL enables flexible queries; Grafana is used for visualisation.

Telegraf is a plugin-based metrics agent by InfluxData that collects measurements from operating systems, services, databases, and hardware through hundreds of input plugins and forwards them to InfluxDB or other monitoring backends.

BorgBackup is a backup tool for Linux that stores backups in deduplicated, compressed, and encrypted form. Deduplication means only changed data is stored with each backup, significantly reducing storage requirements.

Restic is a backup tool that stores backups encrypted and deduplicated to various backends, including local paths, SFTP servers, S3-compatible storage, and Backblaze B2. An alternative to BorgBackup with broader backend support.

ZFS is a copy-on-write filesystem with integrated volume management. It provides RAID-Z as software RAID, snapshots, transparent compression, deduplication, and continuous data integrity checking, making it a reliable choice for long-term storage.

Astro is a web framework for fast, content-driven websites. It ships static HTML with no JavaScript by default and hydrates interactive components only where they are needed, which keeps pages lean and load times short.

Bash is the most widely used Unix shell and scripting language for system administration, automation, and deployment. Bash scripts reliably automate recurring management tasks in Linux infrastructure without additional dependencies.

Docusaurus is a framework developed by Meta for static documentation websites based on React. It supports versioning, local search, and multilingual content, making it well suited for technical project documentation.

Git is the most widely used distributed version control system and tracks changes to code, configuration files, and infrastructure as code. Local copies allow working without network access and merging changes later.

Gitea is a self-hosted Git platform with code review, issues, CI/CD pipelines through Gitea Actions, and a package registry. As an alternative to GitHub and GitLab, it can be operated on own infrastructure in a GDPR-compliant manner.

Go (Golang) is a compiled programming language developed by Google with built-in concurrency through goroutines. It is suited for system software, network services, and CLI tools, and produces single, statically linked binaries.

HTML and CSS are the foundational languages of the web, with HTML describing structure and content and CSS controlling presentation and layout. Used for static and dynamic web applications, including this website.

Pagefind is a static search library that builds its index at build time and runs entirely in the browser. It provides full-text search on self-hosted sites without a search server and without calling any external service.

PHP is a server-side scripting language for web-based applications that can be embedded directly in HTML. Used for database-backed custom developments with a MariaDB backend.

Python is an interpreted, readable programming language suited for scripting, automation, data processing, and rapid prototyping. Its extensive standard library and large ecosystem make it a general-purpose language.

Ansible is an agentless automation tool that manages configuration, provisioning, and deployment over SSH. States are described in YAML playbooks that are versioned and reproducibly executable.

fastlane is an open-source tool for automating iOS and Android app deployments. Build, test, and signing workflows are defined as code and can be executed reproducibly without manual intervention.

Microsoft Power Platform includes Power Apps for low-code application development and Power Automate for workflow automation. It enables building internal business applications without extensive programming knowledge.

REI3 is an open-source low-code platform for building standalone business applications without cloud dependency. Applications are modelled through a graphical editor and run on self-hosted PostgreSQL infrastructure.

Jitsi is an open-source video conferencing platform that can be fully self-hosted. It offers encrypted audio and video conferencing directly in the browser without installation, along with features like screen sharing, chat, and a shared whiteboard.

Postfix and Dovecot together form a complete self-hosted mail stack. Postfix handles sending and routing as the MTA, Dovecot provides mailboxes via IMAP. TLS, SPF, DKIM, and DMARC secure the mail traffic.

Matrix is an open, decentralised protocol for real-time communication. Messages are end-to-end encrypted and servers can federate with each other, allowing users on different servers to communicate. Element is the best-known client.

Nextcloud is a self-hosted collaboration platform that combines file synchronisation, calendar, contacts, video conferencing, and many additional functions under one interface. Operated GDPR-compliantly on own infrastructure.

Microsoft SharePoint is a web-based collaboration platform for document management, intranets, and team sites. In practice it is used as a structured data store through lists and views when no database infrastructure is available.

VMware AirWatch (now Broadcom Workspace ONE) is an enterprise MDM platform for centralised management, security, and monitoring of Windows, macOS, iOS, and Android devices at enterprise scale, including app distribution and compliance policies.

The Apple App Store is the official distribution platform for iOS and macOS apps. Submission, signing, and management happen through App Store Connect, Apple's developer portal.

The Google Play Store is the official distribution platform for Android apps. Submission, signing, and management are handled through the Google Play Console and can be automated with tools such as fastlane.

Microsoft Intune is a cloud-based platform for mobile device management (MDM) and mobile application management (MAM). It enables centralised management, security, and compliance monitoring of devices and applications in hybrid Windows and macOS environments.

Home Assistant is an open-source home automation platform that integrates hundreds of smart home devices and services through a unified interface. Operated on own hardware without dependency on cloud services.

MQTT is an open publish-subscribe protocol for machine-to-machine communication and IoT devices. It is suitable for resource-constrained devices on narrow network bands and is managed by a central broker such as Mosquitto.

Raspberry Pi is an affordable single-board computer with an ARM processor running Linux. It is used for IoT projects, embedded systems, and educational purposes, and provides GPIO pins for direct connection of sensors and actuators.