EPG ingest systems grab data from a specific source (or multiple sources) and feeds it into a middleware or some other data consumer.
I’ve done extensive work on these in the past years, in the parsing, processing and ingestion process, including reverse engineering middleware databases for direct ingestion that allows to circumvent certain flaws in them (for example for nPVR content).
On some of these projects, I just provide the technological infrastructure (the Asdrubal server, built in C++ with Lua driving the business logic). These systems usually have to be fully redundant and 99.99999% reliable.