Taming the Chaos: Cleaning 10M+ Apple Health Records into a Production-Ready Parquet Lakehouse

If you’ve ever tried to click that "Export Health Data" button on your iPhone, you know the feeling of pure dread that follows. You expect a clean CSV; you get a bloated, multi-gigabyte XML file that looks like it was designed by a chaotic deity. When building high-performance AI models for health tech, Apple Health data is a goldmine—but only if you can navigate the minefield of data engineering challenges. We’re talking about massive data volumes, duplicate entries from overlapping devices (iP