This is a difficult topic. I've found that adhering to TDD is just not realistic in some cases. For example, I'm following the Steve Blank approach of Customer

This is a difficult topic. I've found that adhering to TDD is just not realistic in some cases. For example, I'm following the Steve Blank approach of Customer Discovery, building my MVP. If I take the TDD approach (which takes more time to code a finished piece of functionality), and successfully iterate enough times during the Customer Discovery process, I throw out all of the tests that I built and am now moving onto something different that I've discovered a customer is actually willing to pay for.