Custom web application
A custom web application is software built specifically for your company. It opens in a browser and matches exactly how you work, instead of bending your business to fit a generic tool. Not a brochure site, not an online store: a business tool that does the work your team does today by hand, in Excel, or across five apps that don't talk to each other.
Almost anything is technically doable. The real question is elsewhere: how much it costs, how long it takes, and how to avoid the 40,000 € quote that delivers an empty shell two years later.
Custom is not always the right answer. Let's be clear about that before we talk budget.
You want a brochure site or a blog (Webflow or WordPress does the job for a few hundred euros); you sell standard products online (Shopify exists, don't pay anyone to reinvent it); you just want to test an idea with five customers (a Google Form, a spreadsheet, and three calls validate the need before the first line of code).
You re-enter the same information across several tools, and it gets lost in an email on the way; you pay 400 € a month for a SaaS your team uses as a barely disguised Excel; your process is too specific for any off-the-shelf software; you need to own the code, manage access and roles, take payments, automate follow-ups, handle sensitive data.
An eight-person kitchen fitter running its job sites across twelve Excel tabs doesn't have a website problem. It has a copy-paste problem. That's exactly what a business application solves.
The market will tell you "between 15,000 and 200,000 €", which helps you decide nothing. And that's exactly the problem. On a typical agency quote, a large share of the money does not fund your software. It pays a middle project manager, an overhead structure, a margin, and the back-and-forth of an endless spec document. The part that actually produces code rarely tops a quarter of the quote.
Our stance is different: 5,000 € for a first working brick, deployed live, with the source code that belongs to you. Fixed price. If the scope goes beyond what we can ship cleanly, we cut it into several bricks instead of inflating one invoice nobody controls. For the full ranges, see our page on the cost of developing an application.
Why this price holds today when it was unthinkable three years ago: AI cuts code production time by four, as long as a senior developer orchestrates it. A non-developer who codes "by feel" with AI produces technical debt that costs more to fix than to rebuild. We hand the AI productivity back to the client as a fixed price, not as billed hours.
Two weeks per brick. Fifteen working days and the application is live. Those two weeks cover only the development. All the understanding work — the business, the constraints, the mockups of every screen — happens before kickoff. The developer never codes in the dark. That preparation is what makes two weeks possible, not a team sprinting at nothing.
Discovery call — we understand your business, your problems, and what you concretely do today.
Technical call — we dig into the constraints, your data, the integrations with your existing tools.
A clear spec page — drawn from the two calls. You read it, you validate it. Go or no go, no disguised commitment.
Mockups — every page of the final application. You picture it, you give feedback before a single line of code is written.
Go, the clock starts — fifteen days of development, the application is delivered.
Building brick by brick cuts the risk through small concrete deliveries, instead of promising the perfect application in six months and delivering it in two years.
| No-code (Bubble, Airtable) | Off-the-shelf SaaS | Custom application | |
|---|---|---|---|
| For what | Testing an idea fast | A standard, common need | A specific, lasting process |
| Cost | Low up front | 200 to 600 €/month, forever | 5,000 € per brick, once |
| You own | Nothing, you rent | Nothing, you rent | The code is yours |
| Limit | A fast technical ceiling | You bend your business to the tool | None, it's built for you |
| Right moment | Validate before building | The need fits the standard offer | The standard tool holds you back |
No-code is an excellent starting point to prove an idea has value. The day the prototype becomes a tool your business depends on, you have to move it out of no-code into a real, maintainable application. That's a transition, not a failure.
A document that's dead before it's finished. Nobody reads it in full, it freezes decisions made too early, and it bills months of scoping before any result. One clear spec page is enough to start.
The bigger the scope, the longer, costlier, and riskier the project. A first working brick running in two weeks teaches you more than six months of meetings.
A button is simple to display. What can be complex is the action it triggers. A good technical partner's job is to translate your business idea into the simplest solution that works, not to code everything you imagine.
To choose who you trust with this work, read our guide on picking an application development agency. And for a concrete case, look at custom software.
If you re-enter data from one tool to another, if you pay for a subscription you bend into a spreadsheet, or if no off-the-shelf software fits your business, you probably need custom. Not a six-figure project: a concrete, bounded first brick, live in two weeks.