“Dagger is a key technology to get financial models out of Excel, into a programming language and under tests and version control.”
Big investment banks run on a private Python universe with its own global database, its own job runner and its own IDE. One bank-wide instance of everything. It sounds insane until you remember the alternative was a trader’s spreadsheet named “Final (final) (2).” The banks built a better Excel and then locked it where nobody outside could learn from it.