ChartSentinel is a trading terminal: live charts next to AI signal confidence, sentiment, sector heatmaps and order flow. When the redesign landed, it looked ready to ship. Every board was full and every number was in the right place.
The catch was that none of it was real. Each page was drawing from sample data written to make the design look good.
Why that happens
Designing with placeholder data is normal. It lets you get the layout right before the backend exists. The danger is that a finished-looking screen hides how much work is left, and the gap only shows when real data arrives with real gaps, delays and edge cases.
One data layer, one page at a time
Instead of patching each page, we built a single live data layer that every page reads from, backed by the typed API that serves the signal engines.
Then we moved the pages over one at a time and checked each against the real numbers before touching the next. When something looked wrong, we knew exactly which page and which call to look at.
Last, we added auto-refresh, so the boards update on their own without a reload, which is what a trader expects from a terminal.
What real data showed us
Live data surfaced problems the sample data never could. One indicator scored every single stock as zero, because that data only exists for futures. The engine now marks it as not applicable and rebalances the other weights. The reversal scan went empty on quiet days, so it now shows recent setups as well as today's.
Neither of those would have shown up on placeholder data. That's the real reason to wire up live data early: it's where you find out what you actually built.
