Is there any alternatives to Excel and other spreadsheets software but where 'calculations' in every cell occur writing script using sort of programming languages instead of formulas? Asking this because working with huge formulas have it's own huge limitations and lack of readability. Again, I ask not about alternatives to excel to work with xls files but completely another approach to work with spreadsheets.
Additionally, Excel allows you to create your own custom functions using VBA.
Libre Office Calc also supports user defined functions: https://ask.libreoffice.org/t/how-to-create-a-user-defined-function/34010/9