I've done a bit of research for a couple of engine projects today and turned up these little numbers. Familiar technology to anyone used to working on modern or tuned engines, they use either planetary or gear-train reduction allowing the starter to draw less current and spin faster, while still cranking higher-requirement engines.
Customer has just ordered a "special" for his 20 degree Tdi-on-a-wbx bellhousing conversion. A whopping 2kW reduction geared starter compared to the old VW Bosch 0.9kW