Decide · Lesson 2 of 8
Three filters that separate a one-day product from a six-month one, before you've written a line.
4 min read
Before the next lesson
The first two hours are the most valuable in the sprint, and you should spend almost none of them building. Choosing badly at hour one costs you the entire day; choosing well means the rest of it is mostly typing.
You are not looking for a good business. You are looking for something you can finish. Those are different searches, and conflating them is the most common way this day goes wrong.
Set a timer for ten minutes and write down five ideas. Not good ones — five. Ideas are cheap and you need a field to choose from, because the first idea is usually just the most recent thing that annoyed you.
Good raw material, in rough order of hit rate:
Notice what is missing: markets, trends, and anything you would describe as "a platform". Platforms take a year. You have a day.
Run every idea through all three. Failing one is disqualifying — there is no scoring, no "mostly passes".
One: can it be built today, by you, on the stack from Lesson 4? Be honest about the hidden work. Anything involving payments, real-time collaboration, mobile app store review, or scraping a site that fights back is a multi-day project wearing a one-day costume. If you have to say "the tricky part is…", it fails.
Two: is it obvious to a stranger in ten seconds? Say it out loud in one sentence. If explaining it needs context about your job, your industry, or your particular setup, you will spend the launch explaining instead of the product working. "Paste a job description, get five interview questions" passes. "A workspace for aligning stakeholders" does not.
Three: is it useful the very first time someone uses it? Anything that only becomes valuable after a week of data, three colleagues joining, or a habit forming has no first-day value, and the first day is all you get. Single-session usefulness is not a smaller ambition — it is what makes a launch legible.
If two ideas pass all three, pick using this order:
That third criterion matters more than it looks. There is a stretch late in the day where the novelty has worn off and the finish line is not yet visible. Interest is fuel, and you will be running low.
For each idea you drop, write one line on why. This takes two minutes and pays for itself twice: it stops you relitigating the decision at hour eight, and it leaves you a short list for the next sprint — because the ideas that fail the one-day filter are often the ones worth two weeks later.
Then close the list. The choice is made, and made choices are not reopened today.