I had an ISP customer years ago that had an AAA system designed by people who didnt understand DNS, DHCP or RADIUS. They also had no idea about netflow or SNMP.

The application would log into every router in the network and run a massive, on the fly script to manually create a bunch of PPPOE services, shaping targets for those connections, update firewall rules etc.

It would also run manual mikrotik bandwidth tests across every logical link it was aware of.

The application developers were adamant that this was the best way of doing things, and any disagreement would have them point at their dozen or so customers and boast that they surely wouldnt have been able to hoodwink that many people if they were doing it wrong.

Anyway we took a packet capture of all the every 10 minute script updates and demonstrated those to the customer as a whole number % of their bandwidth to certain smaller sites, and also were able to show them how they stopped getting "My internet goes out every 10 minutes" complaints as we turned off the automatic mikrotik bandwidth tests running every 10 minutes.

But to save their customer the application developers agreed to implement SNMP and RADIUS but they never did. IIRC their fee was a flat 15% of all profits generated by the customer, which was just staggering. And the fee could rise if they asked for support.