.NET Meetup with ChilliCream at Marel

Hey .NET developers in Reykjavík!

The folks from ChilliCream are in town for a couple of days, and we wanted to take the opportunity to meet the local developer community. If you don't know us, we're the team behind the Hot Chocolate GraphQL server for .NET.

Marel kindly offered to host, so we thought this would be a great excuse to get together for an informal .NET meetup, exchange ideas, and dive into some real technical topics. We'll bring a brand-new, code-heavy talk on modern GraphQL in distributed .NET systems, plus a few stickers.

But this meetup is not meant to be one-way. 👉 If you have something you'd like to share, this is the perfect opportunity:

• How you approach problems at your company
• Lessons learned from distributed systems
• A short demo, lightning talk, or open question

Feel free to comment on the event or reach out if you'd like to contribute. Short and informal talks are very welcome. We hope to meet a lot of you at Marel 😀

Talk 1: GraphQL in Distributed .NET Systems: What Works (and What Doesn't)

Michael Staib, Microsoft MVP, GraphQL TSC
Pascal Senn, GraphQL TSC

Distributed systems are hard, especially when APIs, schemas, and service boundaries start to drift. In this talk, we'll look at how modern GraphQL changes the way we design and reason about distributed .NET systems.

We'll start with a concise introduction to GraphQL and then dive into federated GraphQL architectures. You'll see how a single, unified schema simplifies consumption while allowing backend teams to keep services independent. By making service requirements declarative, GraphQL enables validation and composition at build time rather than discovering problems in production.

GraphQL has long grown beyond its original use case of making clients more efficient. In modern systems, it can be used to define a single, cohesive business model across heterogeneous microservice landscapes. The GraphQL type system becomes the centerpiece that projects into different protocols such as gRPC, OpenAPI, or MCP, turning GraphQL into an integration layer that connects systems and forms the backbone for agent-driven systems and agentic UIs.

This is a code-heavy, practical talk. We'll build the API for a small webshop step by step and then extend it by integrating agentic UI workflows using OpenAI's App SDK. Along the way, we'll discuss what works well in practice, where GraphQL shines, and where it doesn't.

You'll leave with concrete patterns, real code, and a clearer mental model for using GraphQL effectively in distributed .NET systems.