Software

How to have your own internal tool built

Marc Cornelius5 November 2026 · 4 min read

Somewhere in your business sits a spreadsheet the whole team leans on. A planning, a list, a sheet full of formulas only that one colleague still understands. It works, until someone overwrites the wrong cell and half the week goes sideways. That is the point where people start thinking about a tool of their own. And that is exactly the right moment, as long as you approach it smartly.

The spreadsheet is not the problem, until it is

A spreadsheet is brilliant to start with. In one glance you see the steps in your process, who does what, and where it grates. But the moment more people have to work with it, or the errors pile up, you get stuck. We replaced a planning that was kept entirely in Excel with a custom planning tool. Since then those sloppy Excel errors simply do not happen anymore. Not because people were careless, but because a sheet does not stop them.

Process first, tool later

Never start with the tool. Start by discovering the whole process, without any technology involved. What is step one? What happens next? And after that? That very spreadsheet is gold for this: it forces you to make the process explicit. Only once you know how it runs in practice do you decide what a tool should do. Otherwise you build a nice shell around a broken process, and then you have a faster way to make the same mistake.

“Do not build a nice shell around a broken process. Then you just have a faster way to make the same mistake.”

A prototype says more than a quote

Once the process is clear, we quickly build a prototype. Something working you can click through, instead of a document full of promises. That saves weeks and removes most of the miscommunication. Note: a prototype is not a finished product, and you have to keep saying that out loud. We have had a client receive a prototype and expect a lot more to be included, and that all extensions would fall within the same price. So we always write down on paper what the tool does and does not do. A prototype shows the workings, the text records the agreement.

The quick win that surprises

Sometimes the gain is smaller and bigger than you think at once. For a client we built our own alternative for digital signing. Previously, signing quotes went by email: the client puts down a signature, photographs or scans it, and sends it back. Frustration and a lot of work. With the custom tool clients sign in seconds. They saved money and quotes got signed at lightning speed. One small intervention, and a whole process that suddenly runs smoothly.

Building fast is not building finished

AI makes building a prototype dirt cheap and fast. But easy to start is not built to last. The last twenty-five percent is where the value sits: a user structure so multiple people can work safely, permissions, security, and hosting within the EU in line with GDPR. Exactly the part where a beginner gets stuck. We spoke to an entrepreneur who had built his own CRM that ran locally on his laptop. Worked fine, for him alone. The moment he wanted to give others access, he hit a wall. He did not know how to go from local to live, and to do so safely.

Where the human decides

The machine builds, the human decides. AI is fast but has no taste and tends to be a bit too eager. That is why for us a developer is always on the review before anything goes to production, certainly for tools with sensitive data used by colleagues or clients too. That is humans-in-the-loop: you get the speed of AI, with a human who makes the call and fishes out the blunder before your client sees it.

Your briefing is better than you think

Have you already cobbled something together yourself? Good. That is not wasted work, that is the best briefing you can give us. That entrepreneur with his local CRM could tell us exactly what he wanted, because he had built it himself. We put a user structure on it, in a secure EU environment, and after that he could carry on himself. That is often the ideal route: you know what you need, we make it secure and scalable.

Show us that Excel

Do you have one of those sheets everyone leans on and nobody likes? That is usually the perfect starting point for an internal tool. Book an introduction and just bring that Excel along. Then we walk through the process together and see whether a working tool can take out the manual work. No hourly billing, just a fixed price and a prototype you can see for yourself.