Building an Interactive Cohort Analysis Chart in WPF and What Happens When You Ask AI to Do It Instead

Cohort analysis is a staple of financial and product analytics you group data by time period and track how each cohort behaves across subsequent periods. The visualization is a matrix: cohorts on the rows, time offsets on the columns, values in the cells. Sounds simple. The implementation is anything but, especially when you add interactivity. I built this cohort analysis chart for financial trading analytics — a 13×14 interactive matrix with keyboard navigation, live timer cells, row/column hig