Comment by alexpotato

I've worked at a bank and several large hedge funds.

Some additional interesting tech stories I would add:

- in 2010, the bank had retail Good Till Cancel orders from 1997. I think one was "Buy INTC at $6"

- There is a mix of "I didn't know technology could do this" in the good sense and "I'm amazed this code a. works at all and b. hasn't had an outage in 6 years"

- There is a strong desire, I chose this word carefully, to migrate off of legacy systems. That being said there are several; big issues: 1. it's a GIGANTIC amount of effort with often unclear ROI to the business, 2. upside is capped (maybe you get a promotion) but downside risk is huge (you could tank the business with an outage). 3. Slow, gradual refactors are generally better here but some things can only be "big bang" for various reasons

- You tend to see old but performant and battle tested systems get retired in favor of shiny, new systems with lots of bugs. Why? It looks better on a resume to say "I retired old, crufty legacy system and rolled out a new system" instead of "I refactored old system to be better"

- The complexities are wild e.g. Korean trading requires: a. traders to be licensed in Korea (even if they are working in NYC), b. servers to be in Korea c. tagging orders with not only their executions but also the exchange rate at the time

- There are entire SYSTEMS built to track trade breaks (e.g. Bank A doesn't agreed with Bank B on fill 1248383). Some of these trade breaks are open for for YEARS due to litigation, companies going out of business etc

I could go on and on about this.

If anyone is ever interested in having me on a podcast to talk more about it, I would totally be up for it.