HANDS-ON AGENTIC CODING FOR .NET

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I help .NET developers apply AI agents in their own codebase. We work on concrete tasks, with attention to specifications, context, tests and targeted review.

Schedule an introduction View my offering

Workshop

Hands-on, around a concrete question

Technical pilot

Scoped, in your own codebase

Guidance

Follow-up within an agreed scope

Workshop

Hands-on, around a concrete question

Technical pilot

Scoped, in your own codebase

Guidance

Follow-up within an agreed scope

Sound familiar?

Your developers are experimenting with GitHub Copilot, Claude Code and Cursor. It isn't making a measurable difference yet. The output stays the same, only the tooling changed.

Your backlog is growing, your velocity isn't. AI generates more code and review pressure grows with it. It feels like the tooling changes while the way you work stays put.

You want to see it work in your own code, on a concrete task, with someone who does this every day.

Schedule an introduction

I'm Chaïm Zonnenberg. 20+ years in .NET, 2x cum laude university degree. I build Invullen.nl entirely with Claude Code and use it daily for maintaining Factuur-Assist.nl (135+ customers). That is my daily practice. I share that experience with .NET teams through a hands-on workshop, a scoped technical pilot or targeted guidance.

More about me

OFFERING

What I can do for your .NET team

A hands-on workshop, a scoped technical pilot or targeted guidance.

Agentic coding

I help .NET developers apply AI agents in their own codebase: sharpening specifications, setting up repository context and agent instructions, using agents for implementation and tests, and agreeing on fitting review and verification steps. With Claude Code, GitHub Copilot or Codex, whatever fits your team. We agree on scope and deliverables up front.

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Track record

Daily with Claude Code, since August 2025

on two own SaaS products in production

20+ years of .NET experience and an enterprise security/SSO background

Microsoft Certified AI-103

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Where I come from

Identity & SSO

Implementing enterprise SSO was my work long before I focused on agentic coding, and I'm still asked for it regularly. Is an enterprise deal stuck on a security review or an SSO requirement? I build SSO and SCIM into your .NET SaaS so you get through it, without your team having to become identity experts.

How we work together

From introduction to a scoped engagement

Introduction

We explore your question, your codebase in broad strokes and whether a workshop or pilot fits. We also check whether I'm the right person for this question.

Scoped proposal

You get a proposal with scope, preconditions and deliverables. For example a workshop around one technical question, or a pilot for one type of task in your own codebase. Time and duration are agreed per engagement.

Delivery and evaluation

We work on concrete tasks in your code. I hand over what we set up: explanation, practice, documentation and recorded technical decisions. Afterwards we evaluate and decide whether a follow-up makes sense.

AI-native software development for .NET teams: workshop and pilot

Experience & references

20+ years at ABN AMRO, PGGM, Van Lanschot & more 2x cum laude university Microsoft Certified: Azure AI Apps & Agents & Identity & Access

References from 20+ years of .NET assignments, from the period before my agentic coding offering.

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

Previous clients

Own SaaS products

Factuur-Assist.nl 135+ customers

Invoicing app for freelancers and small businesses. Simple and fast invoicing.

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Invullen.nl Pilot 2026

Exploratory questionnaires for coaches and trainers. Know where your participants stand before the session.

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From practice

Articles on agentic coding, AI adoption, .NET and identity. Honest about what works and what doesn't. (Articles in Dutch.)

Kwartaalplanning op een whiteboard: links gele stickies met features, rechts onder Migratie één roze sticky met (weer) volgend kwartaal

Legacy & migratie 28 september 2026 ·6 min

Legacy: herbouwen of migreren? Met agents kan het ineens wel

Geen tijd voor die migratie? Bevriezen is de derde optie die niemand kiest. Hoe agents mijn Vue 2-migratie van vijf weken naar vijf werkdagen brachten.

Vier collega's kijken geschrokken naar een developer die met het hoofd in de handen achter een monitor zit; tekst in beeld: Eén developer maakte in één middag alle tokens van het hele team op

Agentic coding & workflow 25 september 2026 ·7 min

Tokens steeds op? Koop je abonnement rechtstreeks bij de modelmaker

GitHub Copilot rekent sinds 1 juni tegen API-prijs. Claude Code Max en Codex Pro geven meer tokens per euro: 20 miljard tokens, 13.000 USD vs 180 EUR.

Illustratie: een developer met meerdere armen houdt briefjes met customer_type, API contract, validatieregel, veld hernoemd en DTO vast tussen drie vensters met de repo's identity-service, customer-service en frontend; op tafel liggen de toetsen Ctrl+C en Ctrl+V

Agentic coding & workflow 18 september 2026 ·4 min

Geef je AI-agent een user story, geen repo

Eén user story, drie repo's, drie AI-sessies: dan word jij het klembord. Eén agent-sessie over al je services: parent folder of monorepo met worktrees.

All articles

Frequently asked questions

What is agentic coding?

Agentic coding means building software with AI agents that work autonomously in your codebase: generating code, running tests, refactoring. With tools like Claude Code, GitHub Copilot, Codex and Cursor. You specify, review and steer; the agent does the work.

Which teams do you work with?

.NET teams and developers who work with AI tooling and want to use agents more deliberately in their own codebase. From scale-up to enterprise.

Do you work on-site or remote?

Both. Mostly on-site, some remote. I'm based in the Utrecht area and take on engagements within about an hour's travel.

How does an engagement start?

With an introduction, where we explore your question and whether we are a fit. After that I make a scoped proposal for a workshop or technical pilot, with scope, preconditions and deliverables agreed up front. Afterwards we evaluate and decide whether a follow-up makes sense.

All frequently asked questions

Chaïm Zonnenberg

.NET Developer | 20+ years

Workshops on request · limited room for pilots

Email

info@software-assist.nl

Phone

+31 6 51914406

linkedin.com/in/chaimzonnenberg

Location

Based in the Utrecht area, The Netherlands. Available for on-site and remote work.

Schedule an introduction Prefer to call? Call me LinkedIn

View frequently asked questions

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