Core offer
Prototype sprint: a testable prototype in four weeks
80 working hours, concentrated on the one process that costs you time. No phase with an open-ended result, no hourly billing — a written scope and a fixed price of €4,800.
€4,800 fixed · 40% kickoff / 40% week-3 demo / 20% handover
Next free start: 2nd week of December 2026. At most one sprint runs at a time, so those four weeks are yours.
The prototype sprint is my core offer: 80 working hours, concentrated on the one process that costs you time. No phase with an open-ended result, no hourly billing — a written scope and a fixed price of €4,800.
Next free start: 2nd week of December 2026. At most one sprint runs at a time, so those four weeks are yours.
The weekly plan#
-
1
Requirements are written into the scope sheet and signed off by you. Architecture and UI prototype are built; repository and CI stand up.
Signed scope sheet, clickable UI prototype, repo access
-
2
The core process is built end-to-end with real data. You test internally on your devices.
A testable version of the core process
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3
Edge cases, first live demo, feedback round 1.
Demo on real devices, prioritised feedback
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4
Feedback implemented. Documentation, deployment, handover workshop.
Working prototype, repository, docs, operational handover
Described in more detail on /en/prozess — including what I need from you in each week.
The scope: in writing, with an explicit exclusion list#
In week 1 we write the scope into a scope sheet: every function as a testable statement, for example:
"Ms. Meyer opens the app on her iPhone, picks 'reschedule appointment', sees the new appointment in the list and receives a confirmation e-mail."
The same sheet contains the list of "not in this sprint" — in black and white, what is explicitly not promised. That is the mechanism that makes a fixed price possible at all: the scope is measurable, acceptance is verifiable, and nobody argues in week 3 about what was "meant".
What you have at the end#
Included in the sprint
- A working application of the agreed core process — a Flutter app (iOS/Android/web/desktop) or a Jaspr web application, with a Serverpod backend.
- Real data, not lorem ipsum: your sample data is in, the application behaves as it would in daily operation.
- Repository, documentation, CI: the source code is yours, the docs explain architecture and operation, the pipeline builds and tests on every commit.
- Deployment included: TLS, backups, monitoring — the prototype runs, it doesn't sit on your desk.
- A handover workshop (2 hours) and 30 days of bug fixing.
Not included in the sprint
- Anything not on the scope sheet.
- App store submissions and the waiting times of review processes.
- Native platform features beyond the agreed list.
- Support beyond the 30 days of bug fixing.
- Third-party licences and API costs.
- The guarantee that the prototype becomes a production system without further work — for that there is the build-out and production development.
Acceptance criteria#
Every function on the scope sheet carries a testable criterion. The quality bar for acceptance: demo-ready on real devices, no known crash on the agreed test matrix, no placeholder text in the agreed flows. Acceptance is written, with a five business day review period (§ 640 BGB).
Price and payment plan#
4 weeks, ~80 hours
Prototype sprint
€4,800
Payable in three instalments:
| Milestone | Share |
|---|---|
| Kickoff (order placed) | 40% |
| Live demo in week 3 | 40% |
| Handover/acceptance | 20% |
Payment terms 14 days. Under § 19 UStG (German small-business regulation) no VAT is charged — the stated amount is the final price. Change requests after the scope sheet run through a written change order: what changes, what it costs, what moves.
Your contact person#
You talk to the developer who writes the code. No project manager in between, no handover to a different team. If you have a question about the architecture in week 3, the person who built it answers.
Frequently asked questions about the sprint#
What if in week 2 we realise it isn't right?
Can we extend the scope during the sprint?
What happens after the 30 days?
Is the prototype production-ready?
Which technologies do you use?
Do I need technical knowledge as a client?
How secure is our data?
What does a follow-up project cost?
Next step#
Free 20-minute intro call — you describe your process, I tell you whether the sprint is the right format. Or describe your project in three minutes by e-mail, phone (+49 156 79817895) or WhatsApp. Calls can be held in English; everything written is in German.