Publish early, publish often. Put the code on github when there's something to look at. Write your blog posts as soon as you have something usable. Tell your c

Publish early, publish often. Put the code on github when there's something to look at. Write your blog posts as soon as you have something usable. Tell your colleagues to use it as soon as it brings them value. Do what OP calls "the last 10%" continually while doing the rest, then you don't stand before the false dichotomy of stopping at 90% or not.