Maximilian Köhlenbeck

Lab Notes

Technical write-ups of what I build. Each note covers one project or experiment: what I wanted to build, the architecture, the experiments, what failed, the measurements, and what I would do differently.

Wächter: an offline voice-and-vision assistant for my front door

A fully local voice-and-vision assistant running on an ordinary laptop, with a focus on perception, conversational latency, benchmarking and the engineering failures behind a sub-3-second response target.

Python · YOLO11n · onnxruntime-directml · llama.cpp · Gemma 3 4B · faster-whisper · Silero VAD · Piper TTS · FastAPI

The projects, experiments, measurements and bugs are mine. Claude helps turn my notes into readable articles. I review the technical content before publishing — AI saves me writing time, not engineering time.