I have worked with Marios for over 4 years, in that time he has helped me on numerous occasions. He is an expert at analyzing and understanding complex requirements and then building spreadsheets and workflows so that what used to take 45 minutes can now be completed in less than 10! He has unrivaled knowledge of macros and formulas. A patient teacher who simplifies difficult concepts. I have no hesitation in strongly recommending Marios as both an Excel trainer and business consultant.