Power Query folding notes our mentors actually read

Most folding advice stops at "disable steps until folding returns." That is accurate and incomplete. Our mentors mark up submissions with a three-line note: source, boundary step, and the question the business is trying to answer. That last line matters because analysts often optimize queries that no longer match the decision cadence.

We ask cohort members to snapshot the query plan before and after a change, even if the UI still shows folding. The delta tells a story about cardinality shifts that will bite later when relationships multiply. Keeping those snapshots in a shared notebook builds organizational memory faster than any template library.

Finally, we encourage a weekly ritual: pick one fragile query, annotate the boundary step in plain language, and link it to a visual downstream. When the visual changes, the query annotation reminds everyone to re-run the folding check. It is small, repeatable, and surprisingly calming for teams juggling bilingual field names.