Thirty days is not enough time to build the product you have in mind. It is close to the right amount of time to find out whether anybody wants it, which is a different and more urgent question.
Pick the claim, not the feature set
Start from the single sentence you would need to be true for the product to matter. Everything that does not test that sentence is not in the MVP, however cheap it looks.
This is harder than it sounds, because the cheap features are the ones you know how to build, and the claim is usually the part you are least sure about.
Manual is a feature
If a human can do it invisibly for the first ten customers, it does not need to be built in the first thirty days.
Onboarding by hand, invoices by hand, the entire back half of the workflow by hand. Every one of those is a chance to watch what people actually do, which is worth more at this stage than the automation.
Ship to ten, not to everyone
A launch to ten people you can talk to beats a launch to a thousand you cannot. You are not optimising for volume; you are optimising for the number of conversations per week where somebody tells you the thing you did not want to hear.
