Goldman Sachs are famously the same. Propriety language (Slang), proprietary object database (SecDB) and then a million and one proprietary apps on top of that where a commercial or open source alternative exists. It may have moved on since I worked there, but it seemed to be worth the investment in the early 2000s when I worked there.
Yeah. One of my friends and coworkers started his career at GS around that same time and had some (very!) positive stories about both the tools and the people building them. It sounded like the combination of Slang and SecDB was a real force multiplier for building and evaluating the kind of complex mathematical models he was working on. That's the kind of tool development that shows off just how high-leverage engineering work can be.
My (100% outsider's) impression is that the focus, culture and teams at Goldman Sachs are totally different now thanks to market and regulatory changes, and that it is not a good place to work in a primarily technical sort of role any more.
