Codepocalypse Now: LangChain4j vs. Koog

Abstract

Which Java framework handles AI better: LangChain4j or Koog? In this live coding showdown, we’ll build a semantic code search application from scratch, putting both frameworks to the test. We’ll cover project setup, using language models, setting up a retrieval-augmented generation workflow, and creating a REST API. You’ll see how these frameworks handle embedding generation, vector database integration, and real-world development challenges. By the end, the audience decides who wins—based on which framework gets the job done faster, better, and with less hassle (and whether the demo actually works). This isn’t just a comparison; it’s a live experiment under pressure. Come and see which one comes out on top!