How much does custom software development cost?

Why this a key question

You have an idea.
Your business needs a specific tool to boost, structure, automate its operations.
You feel ready to discuss it with an agency or a provider. Maybe you have already tried some options: generative AI, no-code tools, or even a freelance.

So you naturally come to THE question :
How much does custom software development cost ?

But there is a second, often-overlooked, quest that is far more strategic:
How much will it earn over 6 months, 1 year, or 3 years?

The visible cost… and the iceberg

Thinking that a software can cost 5.000 € is like believing that you can buy an apartment in Brussels for 100.000 €. It's not impossible, but you may ask yourself what is hidden behind this.

A custom software is not a basic service, but rather a strategic asset. It mobilizes several profiles, requires a long-term vision and demands structural decisions for the business.

Why custom software costs (and earns) more than expected

A software is not a finished product. It is a living and evolving product, that must be adapted over time.
Development is a process, not a one-time delivery.

A delivered project is not a finish product

Once the the application is online, the essential work is just beginning :

• User feedback starts coming.
• Unexpected issues start to appear.
• Adjustments become necessary.
• The technological system keeps evolving.

Without proper maintenance, the software :

• Becomes obsolete
• Becomes slow or unstable,
• Is less used, and therefore is less profitable,
• Loses its value until it is abandoned.

A project without maintenance, is a project that slowly dies.

The real cost of software development

Daily rates

In Belgium (and often slightly higher in France), a reliable provider will charge :

• Between 500 and 1.000 € per day depending on :
  • The size of the team,
  • the experience level of the experts,
  • The quality of the process (tests, security, documentation, etc.),
  • The level of support provided.

The required team

Building a professional-grade application requires more than just a developer :

• Functional analyste
• Software architect
• UX / UI designer
• Backend developer
• Frontend developer
• Security expert
• Infrastructure / DevOps
• Project manager
• Business expert

A full in-house team represents an annual investment of between 350.000 et 500.000 €, taking into account not only salaries, but also costs related to recruitment, training, absences, replacements, and HR management.

At KERN IT, you have access to these profiles on a fractional, flexible and adaptable basis to meet your needs.

The importance of the time factor

A quality prototype (not just a clickable mock-up) requires at least 3 months of work from several people.
You should budget 25.000 à 40.000 € for this first phase.
This is a starting point, not a finished product.

Afterwards, you will need to plan for :

• Evolution cycles,
• User testing,
• Functional adjustments,
• A progressive scaling.
  

The cost of on-going evolution

After the inital phase :

• Evolutions requested by users become essential.
• Expectations increase.
• The software becomes central to business processes.

An annual budget from 50.000 to 150.000 € is usually needed to maintain and evolve the tool .
In more ambitious cases, the project can require 1 to 2 FTEs (full-time equivalent), which represents between 75.000 and 150.000 € per year.

The downside of "cheaper solutions"

Some providers offer heavily discount development services. But at what cost ?

• Application developed by a junior, without supervision
• Based on a poorly suited CMS or no-code tool
• No documentation or maintenance
• Fast delivery… followed by radio silence

Result :

• A frozen software
• A heavy technical debt
• A rebuild cost higher than the initial payment.

The trap of choosing the wrong technology

We have seen projects developed with a complex stack, often "trendy" but poorly suited :

• Go + GraphDB + Kubernetes for a simple CRM
• Proprietary stack that is impossible to take over
• Exotic frameworks without documentation

The developer had fun, but the client is trapped.

At KERN IT, our stack is lean, robust, and AI-compatible :

• Python (Flask / Wagtail)
• React / NextJS
• PostgreSQL

We prioritize technologies that are sustainable, maintainable, well-documented.

Freelance vs structured team

A freelance or a solo developer may seem economical, reactive, and flexible.
But they work alone :

• No code review
• No pair programming
• No backup
• No knowledge sharing

It is a risk. And it rarely is a long-term solution.

An entire team, like KERN IT, brings :

• A cross-functional vision
• A rigorous methodology
• A verified quality of production
• A business continuity, even in case of staff absences or turnover.
  

Return on investment (ROI)

The relevant question is not "how much does it cost", but "how much will it earn".

How to Calculate ROI

ROI = (Generated gains - Project costs) / Project costs × 100

But the gains are manifold :

• Time savings (automation, reliability, speed)
• Increase in revenue (access to new clients, loyalty)
• Fewer errors (fewer losses)
• Reduction in software costs (dropping third-party licenses)
• Improvement in team productivity

Example

One of our clients invested 500.000 € over 5 years to develop a custom internal tool, built to absorb a tenfold growth in their fleet.

Without this tool, he would have to gradually triple his team, growing from 10 to 30 employees in 5 years, representing a linear growth of +4 people per year.

This would have required an average of 20 FTE mobilisés every year, leading to a total payroll cost of 8.000.000 € over 5 years.

Thanks to the tool developed, the team went from 10 to 12 people only, an estimated average of 11 FTE, with a true cost of just 4.400.000 €.

Net savings : 3.600.000 €, for 500.000 € invested in the software, meaning a return on investment exceeding 600 %.

This case is a concrete example of how a well-designed tool can sustain major growth while drastically controlling staff costs.

Don't confuse internal tool with a commercial product

Many companies consider this approach :
"We will first build an internal tool. Then, we will sell it to the others."

This logic seems simple, but it is misleading.

An internal tool :

• Is built for a single purpose, in a specific context
• Tolerates shortcuts (UX, security, rights)
• Aims for efficiency, not sales.

A commercial product :

• Must be generic, maintainable, scalable,
• Manages unknown user profiles,
• Requires a product team, a customer support, a comerical strategy.

Transforming an internal tool into a commercial product = 10x increase in budget.

• Internal tool : 150.000 €
• Mature product : often more than 1.500.000 €
  

What your are truly investing in

When you pay for a custom software, you are not just buying code.
You invest in :

• A skilled team that thinks alongside you
• A quality process, user-centric
• A solid technical stack
• A long-term vision
• A tool that will save you time, money, and agility

What KERN IT offers

We are an in-house team of developers based in Brussels.
For over 10 years, we develop custom softwares for companies ready to take the next step.

Our approach :

• Fractional team scaled to your needs
• Transparent collaboration
• Proven technology
• A clear ROI logic
• Projects built for long-term sustainability

In conclusion

A custom software is not just a cost. It is a lever.

• It structures your operations.
• It amplifies your productivity.
• It secure your data.
• It adds value to your company.

If you're thinking long-term, looking for a serious partner, and have a vision to bring to life,Contact us.

We will discuss budget, but also ambition, method, team and return on investment.