Custom software development
Custom software development in the Netherlands, at Crux Digits, means web applications, internal tools, integrations and AI-first systems built next to your ERP and your ICT partner, at fixed prices. One team from audit to launch; you own the code.
Custom software without an open-ended bill. Crux Digits is a software development company in Utrecht that builds AI-first custom software: web apps, AI agents, machine learning models and the integrations with AFAS, Exact, your ERP or WMS that make them useful. One team from strategy to launch, fixed prices, EU AI Act- and GDPR-ready, and you own the code.
Last updated: 14 September 2026
Crux Digits is a custom software development company in Utrecht that builds AI-first products (web apps, AI agents, ML models and integrations) in three fixed steps: an audit, a Production-ready MVP in four to six weeks and a production launch. One named team, 13 published case studies, and the code and IP are yours. In 2024, 22.7% of Dutch companies with 10 or more employees used AI, and in the ICT sector itself 58% (CBS AI Monitor 2024); custom software is how the rest catch up on their own process and data.
What custom software do we develop?
Custom software development is the design and build of software around one organisation's own process and data, rather than configuring a package written for the market average. It fits when the process is the advantage, when the package would need workarounds, or when AI has to run on your own data inside your own systems.
Six kinds of software we build around your process and data, with AI at the core, not a generic tool you have to bend your business around:
Custom web & SaaS applications
Full web applications, portals and platforms, from internal tools to customer-facing products, with AI built in where it adds value.
AI agents & automation
Agents that take actions across your systems: pulling data, deciding within rules, routing tasks and escalating exceptions.
Machine learning models
Prediction, classification and anomaly detection, trained on your own data and deployed inside your stack.
LLM & generative AI software
Grounded assistants and RAG systems built on your own knowledge, with source citation and guardrails.
Computer vision
Visual inspection, detection and quality control, on the edge or in the cloud.
Data engineering & integrations
Pipelines, warehouses and connectors to ERP, CRM and APIs, the foundation every product runs on.
The process
How the work runs
Four fixed steps. You see something real at the end of each one.
Discover
We pin down the users, the workflows and what success actually looks like.
Design
We shape the architecture and UX before a line of code is written.
Build
We develop in short, visible cycles so you see progress every week.
Launch & evolve
We ship, support and keep improving alongside your team.
Why an AI-first software company, and how do we differ?
We are honest about who we are: Crux Digits is not a generic full-stack body shop that takes on every brief. We build custom software with AI, data, machine learning, LLMs and computer vision at the core, plus the web, app, data and integration work a real product needs. If you want a team that actually takes an AI idea to production rather than only advising on it, you are in the right place.
What separates us from a classic software agency is the starting point. A generic agency begins with a specification and builds what is on paper. We begin with your data and your process, pick the use case that moves the needle together, and build a working system that learns and improves. Strategy and engineering sit in one team: no handover to another vendor, no knowledge lost in translation. Want the broader AI angle? See our AI agency in the Netherlands, with the timelines, the handover and what you hold when it is delivered.
Not sure which build to start with? Begin with our AI consultancy in the Netherlands.
Crux DigitsBusiness software built next to your ERP
In an organisation that runs an ERP, custom software is rarely a replacement. It is the part the package handles badly, built beside it, with the ERP as the source of truth. In practice that means three kinds of custom business software:
- A portal for customers, dealers or field engineers, on the data already in your ERP or CRM. See customer portal development.
- A module next to the ERP for scheduling logic, a costing model or an approval flow the package cannot carry without customising its core. See custom ERP extensions.
- An integration between the ERP and the systems around it, so nobody retypes anything. See API integration.
What happens to your current systems?
They stay. We build against the interfaces the vendor itself provides, so a package update does not break the custom software and your ICT partner has nothing to run that it does not know:
- AFAS Profit: through its REST connectors (GetConnectors and UpdateConnectors).
- Exact Online: through its REST API with OAuth.
- SAP: through the SAP Business One Service Layer or the S/4HANA OData APIs.
- Microsoft Dynamics 365: through the Dataverse Web API or the Business Central APIs.
- TOPdesk: through its REST API, for incidents, changes and the knowledge base.
- Your WMS or TMS: through its API or the EDI messages it already exchanges.
If a system has no usable interface, the audit says so before anything is built.
Rebuilding or modernising existing software
An Access database, an old Delphi or VB6 application, or a custom package whose author has left: the risk is rarely the code itself but the fact that nobody can support it any more. We replace such software step by step, module by module, while the old version keeps running, rather than switching over in one go. How the choice between refactoring, stepwise replacement and a rebuild works out: legacy software modernisation.
For IT departments taking on another supplier
When your IT department or ICT partner takes on a software supplier, the questions are organisational more than technical. This is how we deliver:
- DTAP. We build and test in your development, test and acceptance environments; production goes through your own release process.
- Change management. Every release comes with a description of what changes, so your change advisory board can decide on it.
- Documentation and handover. Architecture, runbook, access rights and the source code in your own repository, handed to your team or your ICT partner.
- After go-live. Servers, network and workplaces stay with your ICT partner; we do not take over that role. For AI systems we built ourselves, we offer managed AI support as a separate service.
How custom software development works with us
Three fixed steps with a fixed price and timeline, and you own all the code we deliver. Go from audit to MVP within 60 days and the audit fee is credited in full:
Audit & Strategy: €2,500
In one to two weeks, a prioritised opportunity list with ROI per use case and a clear build plan.
Production-ready MVP: €20,000
Working software on your own data in four to six weeks, built to be kept.
Production Launch: from €50,000
From eight to twelve weeks: a full system, integrated, in production and maintained.
Inside every step we work in one- to two-week cycles (discover, design, build, launch), so you see something working every week rather than a status report. Tests, audit logging and access control are part of the build, not the handover.
Software development agency or in-house team?
An in-house team pays off once software work is continuous: a product that changes every week, a backlog that never empties. For a bounded system, a first version or an integration that has to be right once, a fixed-price agency is faster and costs less per delivered outcome, and you keep the code. The middle path works too: we build the first version and hand it to your developers with documentation and a runbook. The trade-off is worked through in agency or in-house team, with the cost, the time to value, and the people you would have to hire and keep.
What does custom software development cost in the Netherlands?
Custom software development in the Netherlands typically bills €80–€150 per hour, and projects vary widely: a small custom build €25,000–€75,000, a mid-sized platform €75,000–€200,000, and complex systems above that. Hourly engagements are open-ended: the final bill is not fixed up front.
Crux Digits quotes fixed steps instead: audit €2,500, Production-ready MVP €20,000, production from €50,000 (excl. VAT), each with scope and timeline agreed before work starts. The audit always includes a projected ROI, so you know the return before you commit. See the custom software costs per phase and our pricing.
Custom software from Utrecht
Crux Digits works from the Utrecht region; the office is in Nieuwegein. With organisations in the province of Utrecht we sit at the table on site for the audit, the workshops and the handover; elsewhere in the Netherlands we work remotely, with on-site meetings where the work calls for them. For Flanders there is a separate page: custom software development in Belgium. What we built before is in 13 published case studies.
Which software development services do we offer?
Everything you need to build and launch AI-first software. Explore all services:
Related pages
Explore how our software, AI and data expertise come together:
Frequently asked questions
How much does custom software development cost in the Netherlands?
Are you a software development agency or an AI company?
Can you build an AI software product from scratch?
Do you do machine learning software development?
Who owns the code?
Which technology stack do you build on?
Can you work with our existing developers?
How fast can you start, and what is the process?
Do you work in an EU AI Act- and GDPR-compliant way?
Which companies is custom software the best choice for?
For companies whose process, the one customers choose them for, does not fit a standard package. Buy what looks like every other business, such as accounting, HR and a standard CRM, and have only the distinctive part built: scheduling logic, a link between AFAS or Exact and your own systems, a portal for customers or field engineers.
- Custom software pays off when you would have to bend a package so far that every update breaks something.
- A package wins when your process is standard and you see no advantage in it.
- The four deciding questions: custom software or a package.
Can you extend an ERP system without replacing it?
Yes, and it is usually the better route. We build alongside the ERP: integrations through the API of AFAS, Exact or your own package, a module or portal for the part the ERP handles badly, and, where it pays, AI functions on the data already there. The ERP stays the source of truth.
- Replacing it only makes sense when the package itself is the limit, not one missing feature.
- Worked through: AI on an existing ERP, without replacing it.
Who can build custom software in the Netherlands?
Which company should I hire for custom software development in the Netherlands?
It depends on what you are building. Large programmes suit established IT firms, consumer apps suit product studios, and tightly scoped work suits a boutique. Offshore is less expensive per hour but costlier in coordination. Choose on the shape of your project, not agency size.
- Dutch agency rates cluster around a €75 per hour median; offshore providers often sit at €25–€50.
- Always ask who owns the code and whether you can switch supplier without a rebuild.
- Crux Digits fits AI-heavy custom software next to an existing ERP and IT landscape: fixed price, one named expert, you own everything.
Should we hire a Dutch developer or go offshore?
Offshore is less expensive per hour; Dutch is less expensive per delivered outcome. On a tightly specified project offshore often wins on price. On work where scope sharpens during the build, which is nearly always true of AI, you pay the difference back in coordination.
- Time zone, language and GDPR accountability are the three things that go wrong in practice.
- If your software touches personal data, EU hosting and a processing agreement are not a detail.
What is included, and what is not
So you can price the gap before a call rather than after one.
In scope
- Software around your process. Built on the systems you already run (AFAS, Exact, an ERP, a WMS or TMS) through their own interfaces, not a parallel island.
- Something working every week. A visible increment you can click, so the project is judged on what runs rather than on a status report.
- Tests, documentation and a handover. Enough that a developer who has never met us can pick it up.
- The code, models and prompts. In your repository, under your licence, with the documentation. You can hand the whole thing to another supplier and have them continue.
Not in scope
- Infrastructure, service desk and systems management. We are an AI partner, not an ICT partner. Your existing supplier or internal team keeps the estate, the workplace and the helpdesk, and we build inside their standards.
- Third-party licences and usage costs. Model and API usage, and any SaaS the solution calls, are billed to you directly so you see the real running cost. We set a ceiling and an alert rather than an estimate.
- KvK 87456346Registered in the Dutch Handelsregister
- Since 2022Crux Digits B.V., Utrecht region
- 13 casesPublished, each with its own number
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Real Crux Digits engagement; client name withheld pending permission. Capability described as delivered. No published outcome metric is claimed.
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