Projects

A selection of completed projects in software development, system integration and digital transformation.

Web interface of the WhatsApp Business API with conversation list and search

System integration 2026

Custom WhatsApp Business API with web interface

A WhatsApp Business interface that does not run through an external provider but locally on your own server. The goal was GDPR-compliant customer communication – the standard WhatsApp and WhatsApp Business apps were not suitable for that.

Runs on your own infrastructure – the data stays under your control
About €5 hosting per month or just electricity costs instead of roughly €80 per month with an external provider
Web interface with conversation list, search and new conversations

WhatsApp Business API
DSGVO
Self-Hosting
Web-App

Home page of the Kleine Auszeit Lachendorf website with online booking

Web development & booking system 2026

Website with integrated booking system: Kleine Auszeit Lachendorf

A website for a massage studio with its own booking and payment system. The owner releases appointments through an easy-to-use interface, and customers book, pay, cancel and reschedule on their own.

Releasing appointment slots in a calendar – easy to use, no technical knowledge needed
Booking and payment directly on the website, with payment handled via an API of a payment provider
Customers can cancel and reschedule appointments themselves
No ongoing fees for external booking portals such as eTermin, only hosting or electricity costs

Website
Buchungssystem
Online-Zahlung
Zahlungs-API

Visit the website ↗

Why custom development

Your benefits

Off-the-shelf platforms and providers often charge permanent monthly fees. A tailor-made solution costs money once to develop and afterwards only its operation – the development costs pay off in the long run.

approx. €5 hosting per month instead of roughly €80 with an external provider

≈ €900 saved per year in the WhatsApp project

€0 ongoing fees for plugins and booking portals

Invest once, save permanently

Instead of monthly subscription or licence fees you only pay for hosting or electricity. In the WhatsApp project that is about €5 instead of roughly €80 per month – around €900 saved per year. The development costs pay for themselves over time.

Data sovereignty and GDPR

The solution runs on your own infrastructure. Customer data stays with you and does not flow to external providers, which makes GDPR compliance considerably easier.

Exactly the features you need

No unused features and no compromises in your workflows. Custom features and adjustments are possible at any time, also later on.

Independence from vendors

No price increases, no features being dropped and no switching effort because a vendor changes its offering.

Your own website instead of a site builder

Site builders such as Wix or Jimdo tie you to existing layouts and leave little room for customisation. Extra features such as a reviews plugin often cost extra, e.g. about €6 per month. Such features can be built yourself as well – without ongoing plugin fees and exactly the way they fit your brand.

Whether custom development pays off depends on the individual case. I am happy to work it out with you, without obligation.

A similar project in mind?

Briefly describe your task – I will get back to you with an assessment.

Request a project