What to skip on day one

The default answer

Skip it. For project #1, skip almost everything that isn't your one core feature.

Skip these on day one

• Authunless each user needs their own private data
• Paymentsunless you already have someone trying to pay you
• Admin panelsyou're the admin, use the database directly
• Email sendingyour phone works fine for now
• Onboarding flowsyour app should be obvious without one

When to add them

When the absence of the feature is the *only* thing stopping a real user from using your app. Not before.