Petrichor reporting

The ritual

Every Monday, four people exported four spreadsheets, pasted them into a fifth, and argued for an hour about which numbers were current. The company did not need a dashboard. It needed the argument to stop.

Designing for disagreement

The interesting work was not the charts. It was answering, on screen, the three questions that caused the Monday argument: where did this number come from, when was it last refreshed, and who changed the filter.

• Provenance on every figure. Hover or focus any number and it names its source and its timestamp.
• Filters that are visible and shareable. The current filter state lives in the URL, so “which view are you looking at” is answerable by pasting a link.
• One primary series per chart. Everything else is context, drawn in grey. Colour is reserved for the thing the chart is actually about.

Accessible by construction

Charts are where colour accessibility usually collapses. Every series pair in the spec is documented with its contrast ratio, and no chart relies on hue alone — each series carries a distinct shape or position as well.

What shipped

A single screen, a written chart specification covering axes, empty states and loading behaviour, and a colour set the team could extend without breaking contrast.