The app I have been developing for a year at work has 3 source files in the app target and 26 internal Swift packages, each with 2+ library products. It was easy to set up, is easy to grow reliably, and has big payoffs–my average build time is 7 seconds, across 228 builds in the last week.
@kyle nice, do you enforce any constraints in terms of dependencies between the packages to prevent it becoming dependency hell?