In my experience this is a pendulum. Traders hire a few desk developers who are paid by the business, and who work directly with the traders in the same physica

In my experience this is a pendulum. Traders hire a few desk developers who are paid by the business, and who work directly with the traders in the same physical area. They crank out code under a lot of pressure for fast turn around, and eventually it becomes completely unmanageable and / or there is some disaster in production. At that point the technology organisation starts taking by over, the desk developers are let go or they move into technology and start getting paid by technology instead of by the business. Things are now done in a more normal enterprisey software development way, and things are generally done more safely, with more design up front, and more documentation. Of course it also takes a lot longer to get anything done. So traders decide to hire a bunch of developers, answerable only to them, and back to the start we go...