Until you are making a million a year in revenue, it is a waste of time to write tests.
Your startup is going to change so much. Everything is so uncertain and failing. It makes no sense to do anything that does not directly impact revenue until you are making good money.
Run though your service/site/app manually as a user sure. Fix the bugs that are worth fixing. You have years to refine your block of marble into David, for now just take out the big, easy chunks.
Don’t fall into a tech geek stereotype of always starting and never finishing. Claiming everything must be polished and tested and documented is the worst form of procrastination because it makes it sound important and a valuable use of your time.
The startup story is a cliché now for a reason. The guy who throws up a 3-day MVP every week for a year gets rich. Rovio made 51 failed games before they got billions from Angry Birds.
Always, always follow the money. There’s no technology companies. There’s no logistics companies.
They are just companies.
And they all have to follow the only rule of business: Make money.