How an experienced developer teamed up with Claude to create Elo programming language

feature Bernard Lambeau, a Belgium-based software developer and founder of several technology companies, created a programming language called Elo with the help of Anthropic's Claude Code.

Starting on December 25, 2025, he published a series of posts about the project. The first post names Claude as a co-author.

"In roughly 24 hours of collaboration, we built a complete expression language with a parser, type system, three compilers, a standard library, a CLI tool, and a documentation website. Not bad for a day's work,” Lambeau and Claude wrote.

"Elo isn't just a demonstration that AI can write code. It's a demonstration that humans and AI can build together – each contributing what they do best,” they added.

As an expression language that compiles to JavaScript, Ruby, and SQL, Elo is intended as a portable way to handle form validation, e-commerce order processing, and subscription logic.

Lambeau, founder and ...