datly.eu, foldly.eu and incomly.eu all follow the same pattern: a tool I need myself, built in the evening, ad-free and hosted in Germany. How I get there, from the first idea to go-live, has stayed remarkably consistent across three projects, and that repetition is no accident.
Where I start: with my own annoyance
Each of these projects began with being annoyed, not with a business idea. datly exists because a simple scheduling poll on Doodle now means a three-layer cookie banner and a „Pro” upsell. foldly came about because I would not trust an NDA to just any PDF tool that pushes the file onto a stranger’s server. And incomly is there because the usual gross-to-net calculators manage to be wrong on top of their ad banners.
The filter is always the same: would I use this thing myself, regularly? If not, I do not build it. That sounds trivial, but it sorts out most ideas immediately and makes sure I am the first honest user.
How I go about it: small stack, small first step
First I pick the most boring stack that gets the job done. For datly that is PHP 8 on classic shared hosting, for foldly and incomly it is Next.js as a static export. The choice follows the problem, not what looks good on a résumé. A tool that should just keep running for years does not want a pipeline I have to maintain.
Then I build an MVP that does exactly one thing well, and I put it online early. foldly launched as a phase-1 MVP, client-side tools first and server tools later. incomly went live as a plain main calculator before the special calculators arrived. The rest of the roadmap then almost writes itself, because real usage quickly shows what is actually missing.
And privacy is architecture from the start, not a banner. Wherever possible, no data leaves the browser: incomly computes your salary entirely locally, foldly processes PDFs in the browser instead of on the server. That is not a setting added later, it is the first decision.
What comes out of it
The result is the same every time: a tool with no ads, no cookies, no forced sign-up, GDPR-compliant and hosted in Germany. That is the common thread all three share, and the reason they belong together even though they are technically different.
What happens next is substance rather than new features. incomly’s calculation now sits behind 76 automated tests. A year after launch, datly got a complete redesign with a security audit and its own design system, and incomly matured to version 1 with a company-car calculator. The interesting work is often not the first launch, but what quietly gets better afterwards.
What I have learned so far
Four things I take away from the three projects:
- Boring tech is a feature. PHP on shared hosting or a static export are unglamorous, but they run without maintenance and force me into a small, clear code base.
- The MVP is allowed to be small. Going live early is worth more than a complete idea in your head. Real usage tells me what comes next better than any planning could.
- Accuracy beats feature count. That incomly landed 4 euros off the official calculator, where commercial tools were 2,000 euros off, is worth more than three extra functions.
- A framework is a great start and eventually a brake. For the datly redesign, moving from Bootstrap to a custom system paid off, because the project is small enough that one person can hold all of it in their head.
The real gain, though, is a different one: my days are about strategy, architecture and teams. Building things myself in the evening keeps the bridge to the technology intact and makes me better in exactly the discussions I have at work.
If you want to see what comes out of it, everything is on the projects page. And if you tinker with a tool like this yourself, or have an idea for one, I would love to hear from you via the contact form.
