Amaury Anciaux When models become too complex: Excel vs Power Query vs River If your Excel model has become slow, fragile, or difficult to update , you are not alone. Many Excel users eventually reach a point where formulas become hard to manage. The good news: you can improve... Mar 11, 2026
Amaury Anciaux Safely combining tables in Excel: Fomulas vs. Power Query vs. River When you need to combine tables in Excel, the usual approach is using formulas like XLOOKUP or INDEX-MATCH . This works for small datasets that never change but is not reliable: Duplicates in the look... Mar 11, 2026
Amaury Anciaux Quantifying the spreadsheet modeling risk Why quantifying modeling risk matters When testing the ideas that eventually led to River, I spoke with many analysts who build decision-support models in Excel. Almost everyone told me the same thing... Nov 7, 2025
Amaury Anciaux 12 treacherous Excel errors What are treacherous errors? Many formula configuration errors in Excel result in visible errors that propagate all the way down to your final output sheet. Think of using a reference to the wrong cel... Oct 30, 2025
Amaury Anciaux The 4 critical mistakes in Excel VLOOKUP formulas These 4 mistakes are critical because they lead to silent errors , which are very difficult to identify and debug. The following picture shows what you should pay attention to: The truth is, this pict... Oct 28, 2025