I sometimes have a hard time figuring out what shouldn't be built.

The next best thing is to rapidly build the crappiest thing that kind of works. Being a little bit bad on purpose usually helps. Getting trapped in clean code and test coverage ideological hell is precisely what we want to avoid.

I've found that the more aggressive you make your time constraint, the less likely you will wind up committing to some kind of engineering decision that ruins the whole pie.

If the 90 minute rapid prototype doesn't make sense, you didn't waste that much time. It's a lot easier to prove things to stakeholders this way too.

I've turned multi-month product roadmap expansion packs into single day tasks by building the right things at the right times in order to discover what not to build.