Specialist .NET Developer | AI & Identity

Sound familiar?

Your team spent two sprints on a POC that never made it to production. The backlog keeps growing. Your best developers are stuck on unfamiliar territory instead of building features.

Meanwhile, your enterprise prospect is asking when SSO will be ready. Your competitor already has it. And every week of delay costs you momentum.

You're not looking for extra hands. You're looking for someone who's solved this before.

Discuss your backlog

I'm Chaïm Zonnenberg. 20+ years in .NET, 2x cum laude university degree, Microsoft Certified Identity & Access Associate, 4 SSO implementations at organisations like ABN AMRO. I also build my own SaaS products with 135+ paying customers. I work 2 days a week with your team, deliver fast, and transfer everything.

More about me

EXPERTISE

Where I make the difference

I focus on the technical challenges where internal teams often lack the time or specific expertise.

AI Integration

Your competitor already has a chatbot. Your team wants one too, but nobody has the experience. I build a working POC fast, so you show the next steering committee that your team is moving on AI.

Identity & SSO

Your enterprise client demands SSO. The deal is under pressure. I build enterprise-grade authentication, so that deal no longer falls through on SSO and your client gains confidence.

Responsible Generative AI Development

Your backlog is growing faster than your team can keep up. I deliver complex .NET features with AI tooling in a fraction of the lead time. But I also show your team how: they learn to work with Claude Code and Copilot in a responsable way, so your velocity goes up permanently.

Technologies I work with

.NET C# Azure SQL Server OpenID Connect Entra ID Claude Code OpenAI Semantic Kernel

Discuss your backlog

How we work together

From problem to working solution in three steps

Introduction

A 30-minute call. I listen, ask questions, and give you an honest assessment: whether I'm the right fit and how I'd approach it.

Fast onboarding & first result

I dive into your codebase and deliver a concrete result within the first week. No months of onboarding. At ABN AMRO I was productive within days.

Push through

Those complex features your team kept postponing? I push through. I switch quickly between architecture and code, and transfer knowledge so your team carries it forward.

Experience & references

20+ years at ABN AMRO, PGGM, Van Lanschot & more · 2x cum laude university · Microsoft Certified Identity & Access

Complex migration project delivered successfully

"Chaïm managed a large and complex migration project for us and brought it to a successful conclusion. He got up to speed exceptionally fast and consistently made the right decisions based on his deep knowledge of .NET and SQL Server."

Cees

Software Architect at multinational

Proactive from day one

"Chaïm is a true professional. One you don't want to let go from day one. Proactive is his motto. He picks up what matters and doesn't let go until it's resolved."

Robert

IT Team Lead at financial institution

Advised the board on architecture

"Chaïm filled the advisory role of Software Architect at our organization. He advised the board and gave direction to the software architecture. He also guided the development team into the world of microservices and brought knowledge about Microsoft Azure."

Chantal

IT Operations Director