Codepocalypse Now: LangChain4j vs. Koog

A presentation at JNation 2026 in May 2026 in Porto, Portugal by Viktor Gamov

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Baruch Sadogursky × Viktor Gamov — JNation 2026

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WHO WE ARE Baruch Sadogursky @jbaruch Viktor Gamov @gamussa Slides, code & shownotes → speaking.jbaru.ch X/Bluesky: @gamussa | @jbaruch

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THE BUILD — 4 ROUNDS 1 DUMB CHATBOT — prompt → text 2 + TOOLS + MCP — it can act 3 + MEMORY — it remembers 4 + AGENTIC PIPELINE — it selfcorrects X/Bluesky: @gamussa | @jbaruch

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ROUND 1 — DUMB CHATBOT prompt → text 1 CHATBOT ▸ 2 TOOLS ▸ 3 MEMORY ▸ 4 PIPELINE

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Let’s build a REAL agent — in Java AND Kotlin. X/Bluesky: @gamussa | @jbaruch

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ROUND 2 — ADD TOOLS + MCP now it can act 1 CHATBOT ▸ 2 TOOLS ▸ 3 MEMORY ▸ 4 PIPELINE

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ROUND 3 — ADD MEMORY now it remembers 1 CHATBOT ▸ 2 TOOLS ▸ 3 MEMORY ▸ 4 PIPELINE

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Both apps, built from the same tiles. X/Bluesky: @gamussa | @jbaruch

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ROUND 4 — AGENTIC PIPELINE domain modeling + self-correction 1 CHATBOT ▸ 2 TOOLS ▸ 3 MEMORY ▸ 4 PIPELINE

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No loser framework. Both win. X/Bluesky: @gamussa | @jbaruch

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THE WINNER IS THE JAVA DEVELOPER. X/Bluesky: @gamussa | @jbaruch

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As always, have a nice day. @gamussa · @jbaruch · speaking.jbaru.ch