Hey, I'm Carl!

I'm a proud dad. I play badminton, do paragliding and make my own pasta. I enjoy building software on the web platform. Currently I build with TypeScript and Go for the German Airforce.

I organize the Munich TypeScript meetup.

And yeah, my last name is Assmann.

Projects I'm Proud Of

tilly

A relationship journal app that helps me being a better friend. My take on how good web apps can and should feel.

intl

A typesafe internationalization library that does not require code generation

md-ai

A coding agent that runs in the CLI and stores the session as editable markdown

Blog Posts

I write about what I think, learn, do.

Oct 27 2025

A New Kind of Web App

Replicache removed the network from the critical path. Jazz removes it from the architecture. Local-first development that feels like Zustand and syncs like magic.

Oct 1 2025

Making TypeScript Errors Actually Helpful

When building my own typesafe i18n library, TypeScript's default errors became hard to work with. I learned how to create custom error messages that tell you exactly what's wrong and how to fix it.

May 25 2025

AI Agents Demystified: How Simple Loops Power the Hottest Tech

AI agents are magic, but they are simpler than you think. Here’s how agentic automation works and how building for AI will make your software better for humans.

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Latest Recipes

What I have been cooking recently.

Sep 22 2025