Built an AR dashboard that re-ages every invoice from a single As-Of date

I'm a practicing financial analyst and spend a good part of my job building reporting models in Excel.

One problem I kept running into was that most AR aging spreadsheets were static. Every month someone was manually changing formulas, updating aging buckets, or rebuilding pivot tables.

So I challenged myself to build one that updates almost everything from a single input.

Features include:

• One "As-Of Date" that automatically re-ages every invoice

• Dynamic 0–30 / 31–60 / 61–90 / 90+ buckets

• DSO calculation

• Best Possible DSO

• Average Days Delinquent

• Collection Effectiveness Index (CEI)

• Auto-generated collections worklist

• Customer aging summary that reconciles back to the invoice register

The goal wasn't to make something flashy—it was to build something I could actually hand to a controller or business owner and have them use every month.

I'm curious:

When you're building Excel dashboards, what's your biggest challenge?

• Formula complexity?
• Power Query?
• Dynamic arrays?
• Dashboard design?
• Performance on large datasets?

I'd love to hear how other people approach these problems.