Goldman Sachs

On the author's own laptop, firing one updated node costs about 30 nanoseconds, the benchmark for a graph Jane Street now uses to price portfolio risk in real time.

A Notion engineer added that the whole pattern already ships under yet another name, 'signals,' inside Vue, Svelte, Angular, and React tooling. Not everyone was impressed: a quant said he'd built the identical system for his fund seven years ago.

Outside the frontier labs the picture inverts: the top 1% of software companies spend $89k per engineer a year on AI, about 40% of a fully loaded $224k senior salary. The median company spends $137.

One reader flips it: at 40% of an engineer's cost, and near-zero for many use cases, that is cheap, not expensive.

Investment banks run secret forks of the entire Python ecosystem. In Paterson's account, one bank's system reads and writes Python dataclasses straight into a single global object database, called Barbara, shared by the whole firm.

The platform's own source code is stored in that same database, not in files. A thread of ex-bankers traces the idea back to Goldman's SecDB and Slang in the 1990s, and one calls the result "an alternate IT reality" you can't even google your way out of.