Valentin S. Velev

Hello and welcome to my personal website!

My name is Valentin Velev (Валентин Велев) and I am recent MSc Data Science (University of Konstanz) graduate. I have experience in AI (e.g., deep learning, NLP, RAG, agentic AI), machine learning (e.g., regression for prediction and classification, PCA, topic modeling, clustering), data analytics (e.g., EDA, causal analysis, econometrics), and academic research. I previously worked as a data scientist at Codify working on RAG and agentic AI evaluation. My research interest lies in utilizing mathematical models, such as LLMs, to solve complex problems across various academic and industry domains, focusing on education, health care, and climate change.

Note: I am currently looking for an industry job (Data Scientist, AI/ML Engineer, Research Engineer) or a PhD (NLP, CSS). If my profile looks interesting, please do not hesitate to reach out at valentin.velev@gmx.de

PS: If you are wondering where I am in my picture, it was taken in a quaint little French city called Colmar.

news

Sep 21, 2026	Together with my supervisor, Andreas Spitz, I published version of my master’s thesis on the evaluation of document retrieval models on arXiv! Check it out here. We also submitted it to WSDM 2027.
Apr 27, 2026	I got my first CS paper accepted to EuroVis 2026! That is a very nice birthday present indeed :) Check it out here!
Sep 24, 2025	I published my first software package in CRAN, `gglyph`, a tool for visualizing directed pairwise relationships! Check it out here!
Nov 23, 2024	I published my very first paper (on economic inequality) in OUP’s International Journal for Public Opinion Research! Check it out here!

selected publications

Information Retrieval

A Systematic Multi-Domain Evaluation of Document Retrievers

Valentin Velev and Andreas Spitz

2026

arXiv:2609.29455 [cs.IR]

DOI Bib Code

@misc{velev2026reteval,
  author = {Velev, Valentin and Spitz, Andreas},
  title = {A Systematic Multi-Domain Evaluation of Document Retrievers},
  year = {2026},
  archiveprefix = {arXiv},
  primaryclass = {cs.IR},
  doi = {10.48550/arXiv.2609.29455},
  note = {arXiv:2609.29455 [cs.IR]},
}

Visualization

An R Package for Visualizing Significance in Directed Pairwise Relationships Using Tapered Edge Glyphs

Valentin Velev, Johannes Fuchs, and Andreas Spitz

In Proceedings of the 28th Eurographics Conference on Visualization (EuroVis 2026) – Posters and Demos, 2026

DOI Bib Code

@inproceedings{velev2026tapered,
  author = {Velev, Valentin and Fuchs, Johannes and Spitz, Andreas},
  title = {An R Package for Visualizing Significance in Directed Pairwise Relationships Using Tapered Edge Glyphs},
  year = {2026},
  booktitle = {Proceedings of the 28th Eurographics Conference on Visualization (EuroVis 2026) -- Posters and Demos},
  doi = {10.2312/evpd.20261030},
}

Social Science

Economic Inequality and Public Support for Redistribution in Europe: A Cross-Sectional and Longitudinal Multilevel Analysis

Valentin Velev and Alexander W. Schmidt-Catran

International Journal of Public Opinion Research, 2024

DOI Bib Code

@article{velev2024inequality,
  author = {Velev, Valentin and Schmidt-Catran, Alexander W.},
  title = {Economic Inequality and Public Support for Redistribution in Europe: A Cross-Sectional and Longitudinal Multilevel Analysis},
  journal = {International Journal of Public Opinion Research},
  volume = {36},
  number = {4},
  pages = {edae055},
  year = {2024},
  doi = {10.1093/ijpor/edae055},
}