With my extensive experience in the Excel and software development field - spanning over a decade and a half - I am confident in my ability to develop the custom software that you need. Over the years, I have built an arsenal of skills, which include advanced Excel, VBA, macros - all of them being integral for this project. Having dealt with millions of data entries on multiple projects, I'm well-equipped to optimize your calculations for maximum efficiency.
In particular, I believe my expertise aligns exceptionally well with the task at hand; not just due to my knowledge of various Excel functions like SUM, VLOOKUP and IF, but also because of my intimate familiarity with nested functions with iferror and SUMIF. These will be especially crucial in processing the high volume of orders from diverse tables that your project warrants.
Moreover, my proficiencies go beyond just producing quality code - they encompass developing solutions that solve complex problems while providing seamless user experience. A testament to this is my successful career which includes several similar software development projects and advanced-Excel optimization assignments. It'll be an honor to put these skills to use for you and ensure that outputs are error-free and exportable in Excel formats - making it convenient for your further analysis or presentation. Overall, my professional background fits well with your project requirements thereby making me an ideal candidate for this role.