Worked for a car insurance firm about a decade ago and the whole business ran on their Big Iron. I joined the company to work on a customer facing web UI that hooked into an API layer the server group developed to pull data from the Db2.

The callcentre however still used the TUI for all customer inquiries; it was only the customers who got a pretty interface to view their details.

Depending on which system you were logged into, you had a green screen (production) or magenta (development).