Software development company · Amsterdam
We build your software at a fixed price.
Companies and founders bring us the products and features they need: apps, SaaS platforms, AI agents and migrations off old systems. You get a written scope, one price and a delivery date, and you own every line we write. We also build and run four products of our own.
- Fixed price, no hourly billing
- You own the code
- Dutch company, KvK 97437921
- fixed-price builds
- From €5,000
- to a first version, live
- 2 to 4 weeks
- of the code is yours at handover
- 100%
- products of our own
- 4
Selected work
Built here, running in production.
AI agents that book appointments for fitness clubs
For a Dutch SaaS company whose CRM is used by gyms. The agents talk to prospects and members on six channels, book and move appointments, and hand over to staff. The model decides; fixed tools make every change.
Read the case Client project · MigrationReplacing a ten-year-old CakePHP app while it keeps running
A new Laravel API and a React shell take over one path at a time. Anything not moved yet falls through to the old app, with one login across both.
Read the case Own product · Booking software · LiveServeCounter
Bookings, payments and the till for salons and barbers, from €0 a month.
Own product · Evening guide · Live since 2023
DateSpots
Where to go tonight, from reviews by people who actually went. Web and both app stores.
What we do
Four services, each at a fixed price.
Each one starts with a written scope and a delivery date.
MVP development
A first version of your product, live with real users in 2 to 4 weeks.
Learn moreSaaS platforms
Accounts, subscriptions and payments, built to keep running once customers pay.
Learn moreMobile apps
iPhone and Android from one codebase, through both app stores.
Learn moreAI features
Agents, assistants and MCP servers inside your product, with checks that hold in production.
Learn moreThe kind of software company we are
De Bruine Solutions is a software development company in Amsterdam, registered with the Dutch Chamber of Commerce in June 2025. We work with companies, in-house product teams and founders, and every engagement starts the same way: a fixed scope, a fixed price and a date.
Most work takes one of four shapes: a first version that has to reach real users, a platform that has to hold up once customers pay, an app for both stores, and AI that has to work in production and not only in a demo. Sonny Proeger does the work end to end, so the person you talk to is the person who builds it.
You own everything we write. Source code, infrastructure configuration and documentation move to your own accounts at handover, with no licence fees.
More about usOur own products
We build for clients the way we build for ourselves.
Process
How an engagement runs
The same four steps for a single feature or a whole product.
- 1
A free 30-minute call
What you need, what already exists and what "done" has to look like.
- 2
A fixed quote
A written scope, one price for the whole build and a delivery date. If the scope changes, the quote changes with it, in writing.
- 3
The build
Version control, automated tests and a staging environment from the first commit.
- 4
Launch and handover
It goes live, and the code, infrastructure and documentation move to your own accounts.
Questions
Before the first call
What can you build?
New products, SaaS platforms, iPhone and Android apps, and AI features such as agents and MCP servers.
How does fixed pricing work?
After a free call you get a written scope, one price for the whole build and a delivery date. Builds start from €5,000. If the scope changes later, the quote changes with it, in writing.
How fast can you deliver?
A first version is usually live 2 to 4 weeks after the quote is signed. Larger builds get their own date in the quote.
Who writes the code?
Sonny Proeger, who founded the company, from the first call to the launch.
Who owns the code and the IP?
You do, all of it. Source code, infrastructure configuration and documentation move to your own accounts at handover. There are no licence fees.
Where are you based?
In Amsterdam-Zuidoost, the Netherlands. KvK 97437921, VAT NL005270681B48.
Contact
Rather write?
Tell us what you are building. We reply within one working day.
Or email info@debruinesolutions.com
Have a project to hand off?
From a single feature to a full product. Book a free 30-minute call and you get a fixed quote, a delivery date and a straight answer.