BAML Quartz was conceived by a bunch of front-office quants who had not the first idea about the software needs of a big bank beyond the front office. There was an arrogant assumption that front office software is obviously the most complicated/difficult variety of software within a bank and therefore any system designed with front office requirements at the forefront would, of course, be perfect for universal use.

This assumption was challenged at the time by various groups - I was closest to the Equities Operations software team (although not part of it) who absolutely dug in their heels and refused to use Quartz. The assumption was explosively invalidated when people started implementing in Quartz applications that fell under Sarbanes/Oxley regulations and Quartz picked up a severity 1 audit finding - because Quartz was explicitly designed for "Hyper Agility" (literal quote from the quartz docs) - and anyone-can-change-anything-at-any-time does not make for applications that the regulators trust.

There was an interesting trajectory of Python hiring during my time at BAML. I joined just as Quartz was getting started and we managed to easily hire tens of python devs in London because it was easy to sell the fact that BAML was making a strategic investment in Python and therefore their (at the time relatively uncommon) skills would be highly valued. But as Quartz matured, Python developers generally came to dislike it (for reasons see original article) and it became hard to retain the best ones. And after a while Python 2.x became a massive embarrassment and, as Python became a more common skill in the marketplace, it became harder to hire good developers into BAML.