Ask HN: Do you write unit testing when creating a new product?

When you're working on a new product, you want to move fast and release an MVP as soon as you can. This contradicts with the practice to create unit tests for all your code, since unit test code can easily take up 50% of your code base. So my question is: do you write unit tests for your new products? And if not, do you take test-ability into account (i.e. by using dependency injection)?