Services
Four services that fit together. Take a single one, or take all of it from one place, from the first draft to day-to-day operation.
Custom applications
When spreadsheets, email threads and paper reach their limit, you need an application. Design and build from one place (data model, server API, interface, accounts, payments) and day-to-day operation afterwards.
What's included
- Data model and server API
- Browser interface that also works on a phone
- User accounts, roles and permissions
- Payments where they are needed
- Deployment, operation and continued development
Built with ASP.NET Core and Angular, data in a SQL database, running on servers in Europe.
Right for you if an internal process lives in a spreadsheet nobody fully understands any more, or you need a customer portal, a booking system or a management tool.
Case study: Gatherlist

Gatherlist is a guest-list and door check-in system for clubs and events: accounts and roles, lists with rules such as caps and cutoff times, shareable guest links with QR codes, a door check-in screen that syncs live across several devices, statistics with CSV export, and payment through Stripe.
Built and operated by me: data model, API, interface, deployment, domain, mail and day-to-day operation. Four languages, one container, one server in Amsterdam.
Visit gatherlist.ch (opens in a new tab)Case study: TradeBot

TradeBot is a trading bot I built for my own portfolio and run daily. It picks strategies, opens and closes positions, and records every decision.
The craft behind it is the same as on a client project: a .NET application, a database of market data, a screen to look at it, and tests that hold the process together.
Case study: BrunnerWerk CRM

The BrunnerWerk CRM is the tool I run my own business on: customers, projects, invoices and expenses in one place.
It is not off the shelf, it is built around how I work. That is what I build for others too: an internal tool that fits the business instead of the other way round.
Common questions
- What is the application built with?
- ASP.NET Core and Angular, with the data in a SQL database and the application running on servers in Europe. This website is built on the same stack.
- Are there examples I can look at?
- This page carries three case examples: Gatherlist, TradeBot and the BrunnerWerk CRM. Gatherlist is public and linked, the other two run behind a login.
- What is included besides the programming?
- Design and build come from one place: data model, server API, interface, accounts with roles and, where needed, payments. Deployment, day-to-day operation and further development follow.