Charles is an Excel expert who specializes in performance — he is a world leader at making Excel go faster. Once of his specialties is making your VBA UDFs (User Defined Functions) more efficient. After leaving IBM in 1996, he founded a Microsoft Office consultancy and software development company – Decision Models. His special interest areas are: Excel Calculation performance, VBA UDFs & VBA Performance, Excel JS API, Large Excel model, Excel Defined Names, Excel as frontend to Relational Databases, C++ XLLs.

Charles is co-author with Jan Karel Pieterse of Name Manager, a widely-used utility for managing Excel defined names, and author of FastExcel, a commercial product to help optimize Excel calculation speed.

The session of Charles at the conference is titled:  “Excel’s Evil and Hero Functions”

Web site:
www.fastexcel.wordpress.com/