alt Hacker NewsSoftware tends to be complex enough that you need a lot of people and thus a tech company. It rarely makes sense for a company to make their own software that they only use to internally. Many non tech companies makes their own software but it is shipped to customers as part of the product
Eh it depends. I’ve worked at / with a lot of more traditional non-tech companies and you’d be amazed at how a lot of the software looks like Excel circa 1995.
I guess they could be using third party software but it seems like often they are just using an ancient thing they built themselves.