dogfooding
not sure of origins, but a term used in tech - ‘eat your own dog food’, that is to use your own tools, a preference to make things you use yourself and use things you make yourself
benefits include experiential knowledge, familiarity with use cases and likelihood to come across bugs
may produce conflict of interest, preference for your own use case, over others’, slow progress, neglected documentation, etc
often just happens out of necessity - no tech suited to your requirements so you built it ‘in-house’ - but ability to do this is strongly dependent on in-house capacity