"He never created a finished product. Finished products are for decadent minds. His was an evolving mechanism..."
Isaac Asimov, 1964
Related to the over-hyped start-up concept of the Minimum Viable Product (MVP), on which more later, but also related to the Japanese manufacturing concept of kaizen, or continuous improvement, which in turn draws on martial art philosophies (or the power of practice).
Your tech product isn't finished, and isn't going to be. Ever. You might stop developing it and people might carry on using it, and preferably paying for it; but it's not finished. There will always be some improvement, however slight, that can be made to some aspect of it. But more importantly you won't really start to understand what your product does and can do until you make it. Great that you came up with an idea, tweaked it around a bit before realising it. But until you actually have it in front of you, there will be features, UI elements, loads of better stuff to do with it that you couldn't imagine before; and that's nothing to what happens when you put it in front of someone else.
Another lesson to draw is that those changes should be evolutionary as much as possible, at least from the end user perspective. So it's great that you can get a 10% improvement in UI responsiveness by redeveloping the entire back end - but make that change without disrupting the end user. Thought of 6 great ways you could improve the UI? Make them one at a time. Because each is like a product in its own right; seeing the change in use opens up a whole set of possibilities about how the product could be improved.
So make your product work and then improve it; don't be a decadent mind.