Both approaches have their place. If the problem you're solving is best served by an "old fashioned algorithm" you can hook up a side application to your core s

Both approaches have their place. If the problem you're solving is best served by an "old fashioned algorithm" you can hook up a side application to your core system. The interface you define between the side app and core ensures your data never gets into a weird state because your algorithm didn't cover a case. For instance, for some projects we hook up to the Preactor planning system specifically to use their algorithms.