The premise was: avoid visiting clients in person to update music playlists. A system that can be refreshed and updated remotely, using a web browser anywhere in the world, that can be shut down when a client delays payments. 

I hired a group of programmers and set to devise a solution. It required a small, inexpensive computer that was powerful enough to play high-definition mp4 files without glitches. Researched showed that the least expensive that could do it was the platform Intel NUC. 

The software was based on several FOSS technologies. Everything would be running on Linux, Java and VideoLAN Client (VLC). A custom set of libraries were written in Java to create temporary files with the playlists, and keep track on the first and last 20% of the songs played, to always avoid repeats. 

Because every client device would be connected to the internet behind NATs, the server was running a system that would receive pings from each client, in an encrypted JSON message, and expect a response. If the server had “anything new” to tell the player, it’d respond with a flag for the client to pull all the instructions, which in turn would include any links to download from the CDN the industry-compliant encrypted audio and video files, and the channels they would play in.

The system included an invoicing system that would automatically send to each customer digitally signed invoices on their renewal period date.

In turn, the system had to be updated manually by the operator when a bank transfer from the customer (the bar or restaurant) was received on the company’s bank account. If that didn’t happen, the customer should’ve asked for a license extension. Forgetting to do that, the system has had been programmed the month before to stop playing at the defined date, cutting off any music and video from the venue.