Is 100 hours enough?

A 40-hour work year has 2,080 hours per person per year.

The "10,000" hours necessary to be really good at anything number was the expert threshold that they used to categorize test subjects who performed neuroimaging studies while compassion meditating. "10,000" hours to be an expert is about 5 years at full time.

But how many hours to have a good software product?

Usually I check for tests and test coverage first. You could have spent 1,000 hours on a software project and if it doesn't have automated tests, we can't evolve the software and be sure that we haven't caused regressions.