I distinctly remember reading that the entire bill of materials for building a Boeing 747 was managed in Excel. I have not been able to find that claim since then but it was so amazing to me that I remember it.
It doesn't really make sense as I think about it now, because the 747 design predates Excel by many years so maybe it was BS.
Assume that later models of the 747 were managed in Excel. No trolling: What is wrong with that? You can write insanely powerful software using (1) formulas on the sheet (which are essentially functional programming) and (2) imperative logic in VBA (HTTP calls, database calls, file system, etc.). For years, I used this model and wrote pretty powerful software. Sometimes, I miss it for the encapsulated system. These days, in "biz dev" (internal software), it seems like the Excel model was replaced with an Electron front-end (HTML/CSS/JS) with Java back-end.
Because you can't define a named custom formula by composing the built-ins. So every cell is just the same copy-pasted formula string. When you need to change something, you have to change it everywhere and pray that you didn't miss one usage.
I can't count how many times I found a bug in a spreadsheet because someone (who might be me) missed one or two instances.
Yes, you can define your own named custom formulas in Excel.
I prefer to do it with VBA code because I find it easier to manage, but it's also possible without VBA using just the built-ins in the spreadsheet directly.
There's nothing particularly wrong with it, Excel works great. But almost any complex Excel file is riddled with obscure bugs and the nature of the tool makes it impractical to apply some of the most effective quality control techniques. Like you can't easily do code reviews or write an automated test suite.
I second this! Excel is a front end everybody knows and everybody can run. I always got laughed at when I say the biggest competitor of small apps (things like gym diary, meal planner etc.) is excel. Now that it even support python…
I encountered oil wells essentially controlled by post-it notes passed around an office.