I build what has to work. The first time, every time.

Live broadcast production with Castelein AV and First Impact Live. Automation and growth systems for service businesses. Web projects designed and built fast, in collaboration with AI. Three surfaces, one standard.

Eric Zwanenburg
Eric Zwanenburg Builder
30+ years across three specialisms Partner, Castelein AV Co-Founder, First Impact Live AI-native web builds

What I Do

Three specialisms.
One standard.

Different surfaces, the same discipline: rehearsed, redundant, and ready before it matters — whether that's a broadcast going live, a pipeline that can't drop a lead, or a website that has to ship this week.

01

Live Production & Streaming

Corporate broadcasts, hybrid events and multi-site productions where there's no second take — built and directed through Castelein AV and First Impact Live.

Castelein AV · First Impact Live

See the productions

02

Automation & Growth Systems

Website, CRM, follow-up and AI stitched into one connected system — so leads stop leaking and growth stops depending on you.

Business Growth Systems

Explore the system

03

AI-Native Web Development

Web projects designed and built collaboratively with AI — production-grade sites shipped in days, not quarters. This site is the proof.

This site, built end-to-end this way

See how it's built
Portrait of Eric Zwanenburg

About Eric

Thirty years of building things.
One conclusion.

Hospitality taught me service. Technology taught me leverage. Event production — first with Castelein AV, now with First Impact Live — taught me that a broadcast doesn't get a second take. And building sites like this one taught me a website doesn't need a quarter to ship, either.

Across three countries and three specialisms, the pattern never changed: excellence isn't talent. It's discipline, encoded once, running every time.

Anyone can try once.
Few make it hold up when it matters.

Start a conversation

One conversation — about a broadcast, a system, or a website — to see whether it's worth building properly.