I've always heard "tracer bullet" as a request to a production system that selectively gets much more detailed logging or diagnostic output than usual.
Which is to say you haven't read The Pragmatic Programmer? I highly, highly recommend it. I bought my first copy about 8 years ago, and pull it off the shelf once a year or so to freshen up. I always learn something new every time I do.
Users get to see something early on.
Developers build a structure to work in.
You have an integration platform.
You have something to demonstrate.
You have a better feel for progress.
As a solo founder I need working code, that I can put out of mind, while I produce more.