Jonathan Katzy (@katzy_jonathan) profile picture

PhD student, Multilingual LLMs for Software Engineering @serg_delft @AISE_TUDelft

Joined May 2022
Jonathan Katzy retweeted
Closed-source LLMs hide training data. The Poisoned Chalice competition asks: was this code file in the model’s training set? Build membership-inference methods, compete, and present at FSE/AIWare 2026 (Montréal). razvain.github.io/miacomp/ #LLM4Code #FSE2026 #MembershipInference
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Jonathan Katzy retweeted
📣 Exciting competition for the AI & Software Engineering communities! 🎯 Large language models (LLMs) for code are powerful but they often memorize what they’ve seen. When evaluation datasets overlap with training data, reported performance can be misleading
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🧵Introducing "The Heap" - A contamination-free code dataset for fair LLM evaluation! 🔍 The Problem: 90% of code LLM studies don't deduplicate evaluation data, leading to inflated performance metrics @MalihehIzadi @razvanmp27 @avandeursen Thread 👇
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🎯 Impact: Enables reliable LLM performance assessment without the data cleaning overhead. Perfect for researchers who want to focus on evaluation, not data preprocessing! Languages covered: Assembly to Mathematica, C to Haskell, Python to Rust 🌍
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Great insights from @katzy_jonathan! Jonathan Katzy from @serg_delft @AISE_TUDelft just presented "A Qualitative Investigation into LLM-Generated Multilingual Code Comments and Automatic Evaluation Metrics". Exciting work on #LLM #CodeComments #SoftwareEngineering
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Replying to @katzy_jonathan
@katzy_jonathan presenting our #FORGE24 paper on “An Exploratory Investigation into Code License Infringements in Large Language Model Training Datasets”! Talk to him if U are interested in the data used for training a wide range of #llm4code and their implications! @ConfForge
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Are foundation models vulnerable to lawsuits regarding the data they used to train? We analyzed the state of LLMs wrt licenses in public code datasets. Checkout the preprint: arxiv.org/abs/2403.15230 and discuss the implications with me at FORGE/@ICSEconf in April. @MalihehIzadi
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We analyzed the prevalence of exact duplicates of code files with strong copyleft licensed code in public code datasets, and searched the comments of code files to identify strong copyleft licenses.
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We found that even datasets that claim to contain only code from permissively licensed repositories have a large amount of code also attributed to strong copyleft licenses. Raising the question who should be responsible for adherence to code licenses in public online datasets
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Jonathan Katzy retweeted
resulted in identifying 38M exact duplicates in our strong copyleft dataset. This indicates the pervasive issue of #license inconsistencies in #LLMs4Code. We call upon the community to prioritize developing and adopting best practices for #legal & #ethical dataset creation... 3/n
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Jonathan Katzy retweeted
1. "An Exploratory Investigation into Code License Infringements in Large Language Model Training Datasets" 📊 w/ @katzy_jonathan, Razvan Popescu, Arie van Deursen, & @MalihehIzadi Our deep dive into 514 million code files used for training various #LLMs trained on code... 2/n
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Jonathan Katzy retweeted
🎆We're happy to share that 2 full papers from our lab, have been accepted at the International Conference on AI Foundation Models and Software Engineering, co-located with @ICSEconf cc @katzy_jonathan, Razvan, Arie, Tim, Frank, Philippe, Berend, Marc, & @MalihehIzadi #FORGE 1/n
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At @AISE_TUDelft, we're happy to wrap up the year with 2 papers accepted at @ICSEconf (ResearchTrack)🎉 -Language Models for Code Completion: A Practical Evaluation -Traces of Memorisation in #LLMs for Code @aalkaswan1, @katzy_jonathan, @timvandamdev, Marc, Razvan & @avandeursen
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Heartfelt thanks to Prem @devanbu for spending an enlightening week w @serg_delft & delivering a thought-provoking lecture on quality of code generated by #LLMs in our course (ML4SE'23)! I am sure your expertise added a rich dimension to the learning experience of our students.
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Why do #LLMs perform better on some programming tasks than others? In our #IEEESCAM2023 paper, we show early evidence for an inherent difference in representations of tokens between languages. arxiv.org/abs/2308.13354 @MalihehIzadi @avandeursen @ieeescam #ML #LLM #ML4SE
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