You're completely off the mark and are thinking of sales and contracts, not finance. Finance from a company that sells a product or offers a service usually has a few key parts: Billing, Accounts Receivables, Collections, Accounts Payables, Accounting, Treasury, and Payroll ( which is sometimes tied to HR) are the big ones with others in tow.
Ever wonder how your 401k and other deductions get credited every week and all those corresponding companies, including your taxes, get paid to various entities? Payroll and HR does that. Ever wonder who figured out those line items on your bills? Billing does that. Ever wonder how a company funds all of their rent/electricity/payroll/operations on time without sitting on a massive wad of wasted cash but not overdrafting? Treasury does that, AP pays it. Ever wonder how they keep track of all that shit and make sure the right stuff is getting done, nothing more or nothing less? Accounting does that. There's a lot of background stuff that has to get done to keep all this working in a big company.
In my case, I started as what would usually be considered AP, but we had to figure out our own bills based on operational data and pay them with the backup for said bills. Lots of data sources, lots of reporting requirements, lots of special nuances in reporting, so hard to automate but useful to understand how to work with data. Now I'm doing something similar, but with payroll data instead of operations data.