A quick look inside the scanning... this is how you make MS Excel tear:
- adopt an object oriented approach (lock down all objects so users can't inadvertently tank your job)
- use built in functions first (they will always be faster)
- utilize optimized VBA for mild customized functions
- maneuver off tougher things to python
- if you must, utilize c/c (if python wrapped around c is not available)

There is not much you can't do using excel and it allows you to build dashboards on top of an appliion virtually every company has and most people have some familiarity with. As does everything, it does have some pitfalls.

My day in a nutshell...