websystems
David Gstrein
Keep it simple.
Specialist for Booking Systems + E-Commerce
We build software that gets out of the way. That doesn't show off. That simply does its job. So you can do yours.
Our clients are organizations, shops, and businesses across Europe.
Coding agents with senior engineering lead
Today I use coding agents such as Codex and Claude Code for briefing, prototyping, refactoring, and QA. Outcome: shorter iteration loops, faster decisions, and stable software quality through go-live.
Speed with substance
Faster delivery, but focused on the right solution. Business logic first, not demo features.
Experience over hype
Many years of project experience mean clear priorities, robust architecture, and clean releases.
Direct collaboration loops
I used to work with external partners across multiple countries. Today briefing, sparring, and implementation run in one direct flow. The tool landscape is evolving extremely fast, so I continuously adapt to the strongest current agent setups.
Sounds relevant? Send me a short email with goals, scope, and timeline.
Solutions
Booking Systems
Courses & Training
For schools, academies, associations
Events & Conferences
Ticketing, attendee management
Hotels & Vacation Rentals
Reservations with availability calendar
Rentals
Bikes, equipment, vehicles
E-Commerce
Classic webshop with shopping cart, online payment, and order management
Order online, pick up in store – ideal for local retailers
Product catalogs with inquiry modules for business customers
Label generation, tracking integration, pickup management
Own Projects
Conceived, developed and operated - all in-house.
Verleihtool
Software for bike and e-bike rentals. Manage bookings, real-time availability, digital contracts.
- Hotels, rental shops, businesses
- Multi-location support
- No paperwork
Shop-Software
Shop software for businesses that want to sell. Lean and fast without technical overhead.
- One-time license, no monthly subscription
- Stripe & PayPal
- Full data ownership - no vendor lock-in