With LLMs there has been a surge in interest in "specs."

D^[hc]on't write the code, write the spec that tells the LLM what to build, and leave it up to it to figure out the details.

But sometimes you want something a layer below, that includes an opinion about specific parts of the code, but leaves the unimportant details open.

This is less like a PRD and more like a design doc, or even lower, something with the key code sketched out exactly, just the integration bits left unspecified.

it knows how it should work, it just leaves the last details about making everything fit snuggly up to the squishy parts to figure out.

A backbone of a solution.