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. The level is certified as C2 Proficient by an EF SET certificate and can be verified following the link below.

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.

Data analysis condenses raw data such as measurements, events and market data into figures that decisions can rest on. It covers ingesting and cleaning the data, statistical testing and visualization, and pipelines that recompute every result reproducibly from the raw inputs.

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.

Machine learning covers methods by which computers learn patterns from data and make predictions without being explicitly programmed for them. The practical focus is on reinforcement learning and supervised learning, with every trained model measured against a simple baseline.

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

Prompt engineering is the deliberate wording of instructions so a language model reliably behaves as intended. It only becomes dependable through measurement, for example by capturing real requests and re-running them repeatedly with changed prompts.

Speech processing covers speech recognition, speech synthesis and audio data preparation, so machines can understand and produce spoken language. It includes wake-word detection, voice cloning, speaker diarisation and preparing numbers and units for pronunciation.

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.

Experimental design fixes how a test is set up and evaluated before any results exist, so they cannot be bent afterwards. It covers pre-registration, counterbalanced layouts, exact tests and the question of how many measurements are truly independent.

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.

Electronics covers working with circuits, components and boards, from troubleshooting by measurement to soldering. In a smart home setting that includes adapting microcontroller boards and making missing connections yourself.

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.

LLM operations means serving large language models on your own hardware and tuning them for their task. It covers choosing the quantisation, budgeting context and KV cache, GPU utilisation and parameters such as temperature.

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.

Debian is a free Linux distribution known for its stability and long-term package maintenance. It is the base of many other distributions, including Ubuntu.

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.

The Windows Subsystem for Linux (WSL2) runs a real Linux kernel in a managed virtual machine on Windows. Linux tools and containers run right beside Windows applications, including GPU access.

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.

Podman is a container engine without a central daemon that can run containers without root privileges. It understands Docker images and Compose files and integrates with systemd.

systemd is the init and service manager of most Linux distributions. It starts services in the right order, supervises them and restarts them on failure, also as user services without root privileges.

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. This website scores a full 100 % on both the website and the email test, verifiable through the internet.nl badges in the footer.

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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.

Jinja is a templating language for Python that generates text and configuration from data. Home Assistant and Ansible use it for dynamic values in automations and templates.

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.

SQLite is an embedded SQL database that lives in a single file and needs no server. It is the most widely deployed database engine and runs inside browsers, phones and many applications.

Vulkan is the Khronos Group's cross-vendor API for graphics and GPU compute. Software written against Vulkan runs on NVIDIA, AMD and Intel graphics cards without vendor-specific changes.

Chatterbox is an open-source family of text-to-speech models by Resemble AI that clones a voice from a few seconds of reference audio. Its multilingual version speaks more than 20 languages, including German and English.

faster-whisper is a reimplementation of OpenAI's Whisper speech recognition model on top of CTranslate2. It transcribes with the same accuracy in less time and memory, including with int8 quantisation.

Keras is a Python API for building and training neural networks. Since version 3 it runs on TensorFlow, PyTorch or JAX.

LibreChat is a self-hostable chat interface for language models that connects to local and remote providers alike. It keeps several models and conversations in one place.

LiteRT, formerly TensorFlow Lite, is Google's runtime for models on mobile devices and microcontrollers. Quantised int8 models run on the device itself with little memory.

microWakeWord is a framework for training and running wake-word models directly on microcontrollers such as the ESP32-S3. The quantised models fit in the microcontroller's memory and detect the wake word without audio leaving the device.

Ollama is a tool for downloading and running large language models locally. It serves them through an HTTP API and splits them automatically between GPU and CPU.

OmniVoice is an open-source text-to-speech model from the k2-fsa project that covers more than 600 languages. It clones voices from short references and creates new voices from attributes such as age, pitch or accent.

PANNs are neural networks pretrained on AudioSet that recognise sounds in recordings across more than 500 classes. They find unwanted sounds such as clicks or chimes automatically.

Kyutai Pocket TTS is a text-to-speech model with about 100 million parameters that runs faster than real time on the CPU. It streams its output, can clone voices and speaks German and English among other languages.

pyannote.audio is a Python toolkit for speaker diarisation that works out who speaks when in a recording. It is built on PyTorch and ships with pretrained pipelines.

PyTorch is an open-source machine learning framework with dynamic computation graphs and GPU acceleration. It is used to train neural networks, from simple classifiers to reinforcement-learning policies.

Qwen is Alibaba's family of open language models, ranging from a few billion to several hundred billion parameters. The models handle many languages and support tool calling.

Qwen3-TTS is a series of text-to-speech models from Alibaba's Qwen project with 0.6 and 1.7 billion parameters. It clones voices and designs new ones from a description.

Stable-Baselines3 is a Python library of reinforcement-learning algorithms such as PPO, A2C and DQN, built on PyTorch. It trains agents against any environment that follows the Gymnasium interface.

TensorBoard is a visualization tool for machine learning training runs. It plots loss curves, metrics and hyperparameters over time and puts several runs side by side for comparison.

TensorFlow is Google's open-source machine learning framework for training models on CPUs and GPUs. Trained models can be exported for servers, mobile devices and microcontrollers.

vLLM is an inference engine for large language models with an OpenAI-compatible API. Paged management of the KV cache and support for quantised models let it serve large models on a single GPU.

whisper.cpp is a C/C++ implementation of OpenAI's Whisper that needs no Python runtime. Besides the CPU it uses GPUs through CUDA, Metal or Vulkan, so it runs on graphics cards from different vendors.

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.

ESPHome is a firmware framework for ESP32 and ESP8266 microcontrollers that describes devices in YAML configuration. It connects them directly to Home Assistant and installs updates over the air.

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.

The Seeed Studio ReSpeaker Lite is a board with two microphones and an XMOS audio processor that filters out noise. Paired with a XIAO ESP32-S3 it becomes a self-built voice satellite.

The Home Assistant Voice Preview Edition is a voice satellite by Nabu Casa with microphones, a speaker and an ESP32-S3. It is built for local voice control with Home Assistant and can be customised freely with ESPHome.

Wyoming is a simple network protocol that Home Assistant uses to talk to speech-to-text, text-to-speech and wake-word services. It lets those services run on separate hardware and be swapped freely.

IG is an online broker for CFDs and forex with a REST and streaming API. A demo account delivers real market data and real spreads, so trading systems can be tested under live conditions without committing capital.

Interactive Brokers is an international broker with API access to equities, options, futures and forex. Its paper trading account lets strategies and integrations run against the real market before any real money is involved.

OpenStreetMap is a free, community-maintained world map with open geodata. Besides roads and buildings it holds places such as shops with their opening hours, which can be evaluated locally.

Polygon.io, now operating as Massive, is a market data provider for equities, indices, options, forex and crypto. Besides REST and WebSocket APIs it offers historical tick and minute data as flat files, which serve as a base for backtests over many years.