What fits the Sprint. And what doesn't.
A fast sprint only works when the idea matches the model. Most ideas need cutting, not stretching the model to fit them. Here's where the line sits, in plain English.
What fits
Narrow ideas with a clear user, one workflow, and an obvious first version.
The list below is illustrative, not exhaustive. If your idea sounds like one of these, or like a sibling of one of these, it probably fits.
Paid membership platform
Sign up, pay, access content. The whole job is gating something useful behind a wall.
Booking or scheduling tool
Calendar in, confirmed slot out. Niche enough that the giants don't bother.
Client portal
Login, files, status, messages. Replace the 200-email project thread per client.
Assessment / report generator
Inputs go in, structured PDF or page comes out. Productised consulting at its purest.
Niche SaaS dashboard
One audience, one job, one screen. The job that one type of person does every week.
Document generation workflow
Templates, variables, branded output. Boring, useful, lucrative when the niche is right.
Internal CRM-style tool
Contacts, deals, notes, reminders. Replacing the disaster Google Sheet.
Marketplace validation workflow
A first-version flow that doesn't try to be a full marketplace yet. Just the listing-and-contact loop.
What doesn't fit
The kinds of ideas a fast sprint can't do justice to.
Saying no to the wrong fit is the only reason the Sprint stays fast for the right fit. None of these are bad ideas. They just need a different vehicle than this one.
Native mobile apps
App Store review, native UX patterns, push infrastructure. Different beast, different timeline.
Full marketplaces from day one
Trust, supply, demand, payments, disputes. Five products in a trench coat, none buildable as a focused first version.
Multi-tenant SaaS with enterprise SSO
Tenancy and SSO are weeks of work each before they earn anything. Worth doing in version two.
Real-time collaboration tools
Operational transforms, presence, conflict resolution. Hard problems that deserve to be done properly, slowly.
Complex AI agent platforms
Multi-step agents, tool use, evals. Half the engineering is the harness, not the product.
Regulated medical, legal, or financial products
Compliance is the product. The Sprint can't compress that responsibly, and shouldn't pretend to.
Heavy custom design from scratch
If the brand work is the deliverable, the Sprint is the wrong shape; you want a design studio, not a builder.
Large data import or migration projects
Reformatting someone's spreadsheet hell is a separate engagement, and I don't bundle it in.
Anything still in “what are we even building” territory
If that question is open, the Blueprint is the right next step. A Sprint commits to an answer too early.
The other half of fit
The idea has to fit. So does the founder.
A sprint depends on a founder who can describe the problem, decide quickly, and say no to features that don't belong in v1. None of that requires being technical. It does require having thought about it. If your idea is precious to you but you've never been able to describe it on one page, the Blueprint is the right place to start. Not a Sprint.
- You can describe the user, the problem, and the outcome in one sentence each.
- You can reply to a question within a working day during the sprint (about 30 minutes a day, not full presence).
- You can hear “cut that” without it derailing the relationship.
- You have, or can find, the budget without rearranging the rest of your life.
The questions where the answer is sometimes no
If you recognise yourself in any of these, read the answer carefully.
What if my idea is bigger than this list suggests?
Then the first build still shouldn't be the whole thing. “The whole vision” is rarely the right v1. The Blueprint exists to find the version of your bigger idea that fits a sprint: the wedge, the workflow, the test. Most ambitious ideas have one. A few don't, and I'll say so.
I want a marketplace / social network / mobile app. Why is this a no?
Because those products only work at scale, and getting to scale needs ten things to be true at once: supply, demand, trust, retention, monetisation. A focused sprint can't manufacture any of those. What it can do is build the workflow that proves one of them, in isolation. Often that's enough to know whether to keep going.
I have an NDA before I describe the idea. Is that a problem?
Honestly? Yes. I've never seen an NDA-first founder become a great client. Real differentiation comes from execution, audience, and operating advantage, not from secrecy. I sign reasonable mutual NDAs once there's something concrete to discuss, but if the conversation can't start without one, I'm not the right fit.
What if I can't make decisions in 24 hours?
Then a compressed sprint will hurt you. The format depends on you replying within a working day on questions that come up during the build. If you're in court, in surgery, or running a different full-time job that won't release you, the Sprint isn't the right vehicle right now. The Blueprint will still help. It'll just sit on a shelf until you have the bandwidth.
What if I'm earlier than this, just an idea, no audience, no evidence?
You can still order the Blueprint. The most likely answer will be “validate first”, with a specific recommendation for the cheapest test that produces a real signal. That recommendation might save you the cost of a build you weren't ready for. That's the £950 paying for itself.
Find out where your idea sits.
Five-minute Fit Check. Honest written answer back within two working days. If it doesn't fit, I'll say so, and where possible point you somewhere that does.
Check if your idea fits