Phil just talks his way through the overall schematic and design of his RP2040 here.

I’d rate the skill level of this as Tier3: Tier 3: Beyond 20MHz and Leadless Chips. With the VQFN RP2040 package, it is a bit more difficult to solder due to the leadless design and absolutely requires mastery of solder paste + surface mount design.

The overall board design was 4-layers, with signal-ground-ground-signal as per the Rick Harley grounding video’s recommendation (https://lemux.minnix.dev/post/89950)