I once worked at a company that wrote their UI in Delphi but then wrote their logic in C++ using boatloads of COM and MFC (for non-gui elements; the std library with containers was "new" at the time) so they ended up with 20 years of development baggage to talk to SQL Server over ODBC whilst implementing their logic on a repeated basis in C++ (COM loves you implementing interface functions you can't remove), calling from Delphi.

They were trying to port it to a "modern" system and modern compiler so had millions of lines of code to fix, and their UI was MFC-based (so another shot in the foot).

"Fun" times.