The one-page spec engineers actually want.

# The one-page spec engineers actually want

*A NextGen Intelligence template. Fill this in before you brief anyone — an engineer, an agency, or an AI tool — and you'll get a better build, faster, with fewer surprises. If you can't answer a section, that gap is exactly what to resolve first.*

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## 1. The one sentence

In one sentence, what is this and who is it for?

> Example: A booking platform that lets physiotherapy clinics take and manage appointments, with automated patient reminders.

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## 2. The job it does

What does a user come to this to get done? Name the single most important thing.

- Primary job:
- Secondary jobs (only if real):

If you listed more than three jobs, you're describing a roadmap, not a first build. Pick the one that has to work.

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## 3. Who uses it

List each type of user and the one thing they need.

| User type | What they need to do | How often |
|---|---|---|
|   |   |   |
|   |   |   |

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## 4. The core flow

Walk through the single most important path, step by step, as if narrating a user. Keep it to the happy path here — failures go in section 8.

1.
2.
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## 5. What it must do (and explicitly must not)

**Must do** — the capabilities without which it isn't worth building:
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**Out of scope (for now)** — just as important. What are you deliberately not building yet?
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## 6. Data

What information does it hold, and how sensitive is it?

- Main things it stores (e.g. customers, bookings, payments):
- Anything personal or regulated (health, financial, children's data)?
- Where does data come from / go to?

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## 7. Integrations

What does it need to connect to? (payments, email/SMS, CRM, calendars, identity, anything else)

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## 8. When things go wrong

The part most briefs skip — and where production lives. For the core flow, what should happen if:

- A payment fails or is interrupted:
- A required field is empty or wrong:
- The same action is submitted twice:
- An external service is down:

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## 9. Non-functional needs

- Roughly how many users / how much load at the start, and in a year?
- Any uptime, speed, or compliance expectations?
- Devices: web, mobile, both?

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## 10. What "done" looks like

How will you know the first version is good enough to put in front of real users? Write the test you'd run.

> Example: A clinic can set up, take 50 bookings in a day, send reminders, and reconcile payments — without us touching it.

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## 11. Open questions

The honest list of what you haven't decided yet. This is the most valuable section — it's what a good first call is for.

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*Bring this to a 30-minute call with a senior engineer at NextGen Intelligence and we'll turn it into a real architecture and a delivery plan in days. [email protected] · nxtgen-intel.com*