The short answer
Custom software costs the hours it takes, multiplied by the rate of whoever builds it. A senior developer in the Netherlands charges roughly 70 to 125 euro per hour, excluding VAT. The number of hours depends on what the software has to do: a connection between two systems is a few days of work, a platform with users, payments and reports a few months.
Since AI started writing code, that number of hours has dropped sharply, but only for teams that use AI well. That is why quotes for the same idea now differ more than ever. This piece covers what a price is made of, how to estimate it roughly yourself and what to look for when you put quotes side by side.
What the price is made of
A quote for software is a sum. Once you know its parts, you see where the money goes.
Working out what to build
Conversations, sketches and choices about what goes into the first version and what comes later. The smallest share of the hours, and the share that shapes the rest the most.
Design and architecture
What the screens look like and how the software fits together under the hood. This decides whether it is easy to extend later.
Building
Writing the code. AI has made this part the most affordable, because a language model does the typing in seconds.
Integrations
Connections to systems you already use: your accounting, CRM, payment provider or inventory. Often the biggest unknown in a quote, because every external system has its own quirks.
Testing and review
Checking that it does what it should, also when a user does something unexpected, and that the security holds. With AI-written code this part has become more important.
Launch and upkeep
Hosting, monitoring, backups and keeping components up to date. This runs for as long as the software does.
What AI changes about the price
Until a few years ago, most of the hours went into writing out code. A language model now does that work in a fraction of the time. In our own work, productivity is up to ten times higher than with a way of working where developers type everything line by line.
What AI does not speed up is the work around it: deciding what to build, choosing the architecture, reading the generated code and deciding what may go live. That part of the bill stays, and so it weighs more.
Two consequences if you have software built. The same project can take far fewer hours at a studio that uses AI well. And a strikingly low quote can also mean AI is being used while nobody reviews the code. You find out once real users are on it. We wrote about that stage earlier in the last 20% of a vibe-coded project.
AI makes building cheaper. Judging what gets built, and whether it is right, costs exactly as much as it used to.
Three worked examples
The figures below are rounded and assume a senior developer who uses AI for the writing, at 125 euro per hour. They show how a price comes about. Your project can come out higher or lower.
A connection between two systems. Orders from your webshop have to flow into your accounting automatically. Working out how both systems behave, building the connection, testing it with real data and making sure you get an alert when something fails: 16 to 40 hours, so 2,000 to 5,000 euro.
A first working version of a web application. A customer portal where customers log in, see their details and upload documents, with no connections to other systems. Design, build, security and launch: 80 to 160 hours, so 10,000 to 20,000 euro.
A platform with several kinds of users. An environment where customers order and pay, staff handle the orders and reports come out, connected to your accounting. Most of the hours here go into architecture, integrations and testing: 300 hours or more, so from 37,500 euro.
A traditional team that writes the code by hand often bills a multiple of those hours for the same examples, even at a lower hourly rate. That is why the hourly rate on its own tells you little.
The costs after launch
Software that is live keeps costing money. For most business applications hosting is the smallest item, often tens of euros a month. Maintenance is bigger: updating components when a security hole turns up, adapting when a connected system changes and making the small improvements users ask for.
A common rule of thumb is that maintenance costs 15 to 20 percent per year of what the build cost. Include that when you compare quotes. A cheap build that is hard to maintain becomes the most expensive choice within a few years.
How to keep the price down
Start with the smallest version that works
Build what your users really need first and watch what they do with it. Every feature you postpone costs nothing now and sometimes turns out to be unnecessary.
Use what already exists
You do not need to build login, payments or email yourself. Connecting an existing service is almost always cheaper than reinventing it.
Ask for a fixed price for well-defined work
Then the risk of overrun sits with whoever made the estimate. Do ask which assumptions sit behind it, because that is where quotes differ.
Ask who reviews the code
A low price without senior review is a bill that arrives later. The answer to this question tells you more than the total.
What it costs with us
We charge 100 to 150 euro per hour, excluding VAT. The more steadily you work with us, the lower the rate. For a well-defined project we prefer to agree a fixed price, with the assumptions written down, so you know in advance what you are in for.
You work directly with senior developers with 15+ years of experience, who use AI for the writing and sign off on what goes live themselves. What we build and how, you can read on the page about custom software development. If it is an app, see app development. Have you already built something with an AI tool that is not ready for real users yet? Then making a vibe-coded app production-ready is often the cheapest route.
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Want to know what your software costs?
In a free consultation we work it out for your idea, with a range and the assumptions behind it.
