How do you know if your idea is worth building?

Most founders build before they ask. They get excited, set a timeline, and start coding. But if you haven't found real demand yet, you're just hoping the market agrees with you. The first discovery filter is brutal and simple: can you find ten people in a week who genuinely have the problem you're solving?

Not people being nice. Not your assumptions. People who'd actually pay money because they need this. If you can't find them, the idea might be real someday, but not now. The market's telling you something — listen.

The second gate is defining your core feature in one sentence. Can you explain what you're building, the single most valuable thing, without qualifiers or side-features? Most founders realize at this point that what they wanted to build isn't the real problem. That clarity is gold.

Sometimes an idea isn't worth building right now. Maybe the timing's off, or you don't have the right team, or the market conditions aren't aligned. Discovery forces that conversation before you've burned weeks building the wrong thing.