How to brief a developer: the one-page spec that gets you a fixed price
A template non-technical founders can fill in thirty minutes that turns vague quotes into one fixed number and a date.
Douglas Maringa, August 21, 2026
Developers can't give you a fixed price for a vague idea, so they give you an hourly rate, and hourly rates are where budgets go to die. Here is the one page that changes that.
The template
Who uses it. List each type of user. A marketplace has at least three: buyer, seller, admin. Each one is a set of screens.
The one thing each user must be able to do. Not the feature list; the outcome. "A host can list a cabin and get paid when someone books it." If you can't finish that sentence for a user type, cut the user type.
What "done" looks like. The moment you would show it to a customer and ask for money. Be specific: "A buyer pays, the seller gets an email, and I can see both in an admin table."
What already exists. A prototype, a Figma file, a Bubble app, a spreadsheet you run the business from today. Links, not descriptions.
What you already pay for. Stripe, a domain, an email tool, a CRM. Integrations are cheaper when the accounts exist.
What is out of scope for version one. Write this section. It is the one that keeps the price fixed.
Timeline and why. A launch event, a fundraise, a season. Deadlines change what gets built first.
What to expect back
A written scope that repeats your page back to you in the developer's words, a fixed number, and a start date. If the reply is "it depends, here is my hourly rate", send the page to someone else.
The question that reveals everything
Ask: "What happens to the price if I add a feature in week three?" The right answer is "it gets its own quote and you decide." Anything else means the number was never fixed.
At JetBuild every project starts with this page, a 20-minute call, and a fixed price within two days. Send the page to douglas@jetbuildstudio.com or bring it to the call.