Pavel Kordík

Pavel Kordík

Associate professor at FIT CTU in Prague · Co-founder of Recombee

I work on machine learning, and much of it ends up in production at Recombee. I try to use AI to make things around us a little better: recommenders that help people find what they would otherwise miss, AI that is safe for children at school, climate models for cities and forests, and AI agents that work for people.

Research timeline · 2002–2026

My papers and my students' theses, one brick each

Solid bricks are papers, light ones theses. Click a year to zoom in.Explore the timeline →

Projects

Things I build with students and colleagues. Most of them are open and online.

Mind the Alignment Gap: a guardrail built for adults does not protect a child

AI agents and safety

With Jakub Matušek we measure how a shopper's agent and a platform's agent should divide the work, and how easily they are manipulated (IJCCI 2026). With Jan Fikeis we show that general-purpose moderation misses most harms aimed at children (WOAH @ EMNLP 2026).

RecSys Atlas: a map of recommender-systems research

RecSys Atlas

Twenty years of ACM RecSys research on one map: 2,212 papers grouped into 34 regions by what they are about, measured trends, and open problems drafted from the literature.

p-book: How Recommendations Work

p-book: How Recommendations Work

A book about recommender systems that personalises itself with one and lets readers extend it. Readers choose how content is served and told, and watch the mechanisms act on their own behaviour. Demo at RecSys 2026, with Eva Nečasová.

More projects PoliRural+ p-book, SlAIdy, Tiny, textbooks for schools, open source
PoliRural+ interactive knowledge base: nine pilot regions on a map of Europe
New

PoliRural+ policy p-book

The interactive knowledge base of our Horizon Europe project: nine pilot regions and their action plans, EU rural policy, open geodata and the JackDaw GeoAI agent. Twelve chapters, reading missions and mini-games, every claim traced to a public deliverable, and an MCP server so that AI agents can read it too.

colAIborate and SlAIdy: AI for proposals and slides

SlAIdy

A slide editor in one HTML file. The deck stays a folder of markdown and SVG figures, legible to you, to git and to the AI model you edit it with. The research slides further down this page are made in it.

Tiny: chatbots for teaching

Tiny

An AI assistant for classrooms by AI dětem. I advise on the technology and on keeping it safe for children; lesson decks for teachers are built in SlAIdy.

Open source from the group

Research code and data released with our papers.

  • ELSA scalable shallow autoencoder for recommendation
  • SparseELSA ELSA with sparse embeddings
  • beeFormer sentence transformers trained on interaction data
  • SHIELD dataset of harmful and sensitive queries in marketplace search
  • RepSys interactive evaluation of recommender models

Tools and demos

Things made for teaching and for founders.

Business

Companies are how research reaches people. I co-founded three of them and spent seven years as the faculty's vice-dean for industry cooperation.

Recombee: AI recommender and search
Co-founder · since 2015

AI recommendation and search as a service, founded in 2015 with PhD students from my group. Good recommendations help people discover content they would otherwise miss, and help companies make their online products better. I am responsible for the research direction and the link to the university. Together we run Recombee Lab, a joint research lab with the faculty, and Recombee funds industry PhD scholarships; methods such as ELSA, beeFormer and sparse embedding compression came out of this collaboration. The company is led by Tomáš Řehořek, my former PhD student.

500+ customers in 40+ countries and 10,000+ sites and apps, from media such as The Telegraph and DAZN to e-commerce and marketplaces. Annual recurring revenue of about USD 8M.

Joint research that Recombee released as open source:

EduMatch: the career network built for agents
Co-founder · since 2024

EduMatch

Practical experience during studies matters more every year, and it is hard to get. In EduMatch every student has an AI career assistant that finds internships and jobs that fit, does the pre-screening for them and spares them painful interviews they had no chance in. A spin-off of experts.ai.

experts.ai dashboard: a faculty's experts, research outcomes and projects at a glance
Co-founder · since 2017

experts.ai

A search engine for university expertise. Research teams show their results, licences and services, and faculties embed the search on their websites so that companies find the right people and equipment.

Academia and industry

  • Vice-Dean for Industry Cooperation at FIT CTU, 2017–2024: the faculty's partnership programme with companies.
  • Research with companies such as Recombee, ŠKODA AUTO and Meteopress; with Meteopress the group won Weather4cast at NeurIPS 2022.
  • capTTict (Interreg Danube, 2024–2026, completed): CTU led technology transfer and startup support across nine countries.
  • Advising early-stage AI startups, and Tensor Ventures on the AI maturity of potential investments.

Research

What I work on with PhD students and colleagues at FIT CTU and with the research team at Recombee: recommendation and search, trustworthy AI agents, machine learning for weather and climate, and AI for science and learning.

beeFormer: a language model trained on user behaviour more than doubles zero-shot recall
Personalisation & search · Recombee Lab

Language models that learn taste

beeFormer puts a language model inside the training loop of a recommender, and recall on books it has never seen more than doubles (RecSys 2024). CompresSAE makes embeddings 12× smaller and runs in production (RecSys 2025); Sparse ELSA makes them readable (The Web Conference 2026); at The Telegraph, editors use the same idea to see which reader groups engage with which topics.

Super-resolution from rain nowcasting to climate downscaling
Weather & climate · FOCAL

From tomorrow's rain to the end of the century

WeatherFusionNet predicts rain eight hours ahead from satellite images and won Weather4cast at NeurIPS 2022. In the Horizon Europe project FOCAL we bring climate projections from 12.5 km down to under 500 m, with error bars, for city heat and forest growth. This line of work led group members to found Tempest Labs in 2025.

A two-sided agentic marketplace: a buyer's agent, a broker and seller agents
Trustworthy AI agents · PoliRuralPlus

Agents that know the place, the child and the market

The JackDaw GeoAI agent and AgriBot answer farmers' questions with local data. Our guards catch advice that breaks a local rule (44 → 86 % of harmful replies, GeoAI 2026) and harms aimed at children (38 → 99 % recall on our benchmark, WOAH 2026). And when both the buyer and the seller are agents, we measure who should do the work (IJCCI 2026).

AutoResearch: AI agents run the experiment loop, a hidden test confirms the result
AI for science & learning

AI that does research, verifiably

In AutoResearch, agents run the experiment loop and a hidden test set confirms every result. Recommender maths chooses fluid-dynamics models with HZDR Dresden, and machine learning tunes laser–plasma experiments with ELI Beamlines and UC Berkeley. ResearchCoach, our AI mentor, comments on students' research drafts within minutes.

ACM RecSys 2025 in Prague: 1000+ attendees, about 60 % from industry
Prague · September 2025

ACM RecSys 2025 in Prague

With Mária Bieliková and Markus Schedl I was general co-chair of the main conference of the field: more than a thousand attendees, about sixty percent of them from industry, and 440 research submissions. Rodrigo Alves from our group chaired the industry track.

Community & Recognition

Program committees. Senior PC member of ACM RecSys 2024 and 2026 and The Web Conference 2026; PC member of RecSys, KDD, ICANN, IJCNN and other conferences.

Journal reviews. Neural Networks, Information Sciences, IEEE Transactions on Neural Networks and Learning Systems, Machine Learning, ACM Transactions on Knowledge Discovery from Data, Neural Computing and Applications.

Roles. ACM RecSys Steering Committee; General Co-Chair of RecSys 2025 in Prague; Council of the Institute of Computer Science of the Czech Academy of Sciences. Doctoral examiner and thesis reviewer at universities in Prague, Brno, Ostrava and Bratislava.

Best Paper, EvalRS @ KDD 2023 1st place, Weather4cast @ NeurIPS 2022 2nd place, Meta-Learning Challenge @ AAAI 2021

EU Research Projects

European projects where I am the Principal Investigator for CTU.

JackDaw: an orchestrator that sends each part of a question to a specialist model
Horizon Europe · 2024–2026 · CTU coordinates

PoliRuralPlus

Place-based development of rural and peri-urban regions, with 20 partners from 13 countries, 9 pilot regions and 26 open-call teams. Our group builds the AI layer: the JackDaw GeoAI agent, AgriBot, which tells farmers which subsidies apply to their parcels, and safety guards that know the local rules.

FOCAL: from one 12.5 km climate-model cell to a grid under 500 m
Horizon Europe · 2024–2027 · coordinated by Fraunhofer IGD

FOCAL

Local climate information for adaptation planning. Our group leads the AI models: super-resolution networks and Bayesian neural fields bring climate projections from 12.5 km to under 500 m and say how sure they are. They feed two pilots, urban heat in Constance and tree growth in Czech forests.

capTTict Completed

Interreg Danube, January 2024 – June 2026. Technology transfer, company building and ICT innovation across the Danube region: CTU was the lead partner of 16 partners from 9 countries, working with digital innovation hubs and experts.ai. In January 2026 we hosted the ICT Technology Transfer Days at FIT CTU: more than 25 incubated startups from across the Danube region pitched to investors in three tracks. Project page

Non-Profit Initiatives

Two organisations I co-founded: one brings AI education to children, the other builds the AI ecosystem in Prague.

AI dětem logo
Co-founder and technical advisor · since 2021

AI dětem

“AI for children”: a non-profit that introduces children and their teachers to artificial intelligence in an engaging and responsible way. It is an important area that few people work on, and we want to take it beyond Czechia. If that makes sense to you and you would like to help, get in touch.

  • Tiny, an AI assistant for informatics lessons, built with Charles University and funded by the Technology Agency of the Czech Republic and google.org. In the three weeks after its launch on 14 September 2026, 203 schools registered and 495 teachers joined.
  • Child-safe AI. The guard from our WOAH 2026 paper comes to Tiny next, with a human reviewer for flagged conversations.
  • An AI curriculum and living textbooks for children aged 8–15.
  • Roboti Ju a Pí: co je to umělá inteligence, a children's book about AI (Labyrint, December 2026); I am its expert guarantor with Cyril Brom.
prg.ai logo
Co-founder · chair of the executive committee

prg.ai

A non-profit initiative of the City of Prague, Charles University, the Czech Academy of Sciences and CTU. For years we have been building the local AI ecosystem and preparing our society for a big change, the arrival of AI superintelligence, so that the region benefits from it and turns early adoption into future wealth.

  • prg.ai Minor, an inter-university study programme that combines four faculties of CTU and Charles University.
  • A map of Czech AI: companies, research groups, investors and communities in one place, and a network of 40+ member and partner companies.
  • Dny AI and AI Awards, the largest Czech AI festival and the field's professional award, co-organised by prg.ai.
  • Elements of AI in Czech since 2021.

Professional Journey

Academia, companies and non-profits, side by side.

  1. 2007PhD at the Faculty of Electrical Engineering, CTU: knowledge extraction with ensembles of inductive models (GAME).
  2. 2010–2016Vice-dean for development, helping to build the new Faculty of Information Technology.
  3. 2015Co-founded Recombee, recommendation and search as a service.
  4. 2017Associate professor in informatics at CTU.
  5. 2017Co-founded experts.ai, a search engine for university expertise.
  6. 2017–2024Vice-dean for industry cooperation at FIT CTU.
  7. 2019Co-founded prg.ai.
  8. 2021Co-founded AI dětem.
  9. 2024Co-founded EduMatch. Three EU projects start: PoliRuralPlus, FOCAL and capTTict.
  10. 2025General co-chair of ACM RecSys 2025 in Prague.

Teaching

Academic Courses at CTU

Data Mining Algorithms (NI-ADM)

Advanced data mining with a focus on modern recommender systems and search, and the theory behind them, such as the bias–variance decomposition and modelling a model's confidence.

Computational Intelligence Methods (NI-MVI)

Modern AI architectures and optimisation methods, from the theory to working implementations. The course has its own living p-book.

Machine Learning Seminar (FIT-SM, formerly SZ)

Discussions of current AI research and breakthrough papers, where students practise reading critically and presenting research.

I introduced the master's courses Data Preprocessing, Data Mining Algorithms and Computational Intelligence Methods and the bachelor's course Knowledge Discovery from Data at FIT CTU and the Data Mining course at FEE CTU.

AI in my teaching. I try out new ways of teaching together with the students, in courses with dozens of students each semester. NI-MVI and the machine learning seminar run on a collaborative course platform where students extend the course text, and ResearchCoach, an AI mentor we built, comments on their research drafts within minutes.

93master's theses supervised
43bachelor's theses supervised
7PhD graduates (5 as supervisor)
7current PhD students

Want to work with us? Thesis and PhD topics · get in touch

Selected Publications

Selected papers, newest first. For a complete list see Google Scholar and DBLP.

2026

  1. How Would You Like Your Recommendations? p-book, a Self-Recommending Living Book That Teaches How Recommender Systems WorkKordík, P., & Nečasová, E. · Proceedings of the 20th ACM Conference on Recommender Systems, pp. 1811–1813 (2026), demoTry the p-book
  2. Evaluating the Division of Labour in Strategic Two-Sided Agentic MarketplacesMatušek, J., & Kordík, P. · IJCCI 2026, special session AI Agents: Progress, Architecture, and Applications (AIPAA), accepted
  3. Mind the Alignment Gap: Why General-Purpose Moderation Fails Children, and How a Child-Centric Taxonomy and Synthetic Data Close ItFikeis, J., & Kordík, P. · WOAH 2026: 10th Workshop on Online Abuse and Harms @ EMNLP 2026, acceptedCode and models
  4. No Safe Words: Building Shortcut-Resistant Safety Guardrails for Geographically Grounded Environmental AdvicePerles, M., Slyvka, O., & Kordík, P. · GeoAI '26: 9th ACM SIGSPATIAL International Workshop on AI for Geographic Knowledge Discovery (2026)
  5. Hybrid Cold-Start Recommender System for Closure Model Selection in Multiphase Flow SimulationsHänsch, S., Sajdoková, A., Rębowski, A., Miškařík, F., Ramakrishna, K., Schlegel, F., Rybář, V., Alves, R., & Kordík, P. · arXiv preprint arXiv:2604.09112 (2026)
  6. Language Embeddings Meet Shallow AutoencodersAlves, R., Vančura, V., Kordík, P., & Ledent, A. · Proceedings of the 34th ACM Conference on User Modeling, Adaptation and Personalization (2026)
  7. The 19th ACM Conference on Recommender Systems (RecSys 2025)Kordík, P., Schedl, M., Bieliková, M., Pera, M. S., & De Gemmis, M. · ACM SIGWEB Newsletter, Summer 2026, pp. 1-4

2025

  1. Mitigating Risks in Marketplace Semantic Search: A Dataset for Harmful and Sensitive Query AlignmentSpacek, F., Vančura, V., & Kordík, P. · Proceedings of the 33rd ACM Conference on User Modeling, Adaptation and Personalization, pp. 329-334 (2025)
  2. Evaluating Linear Shallow Autoencoders on Large Scale DatasetsVančura, V., Kasalický, P., Alves, R., & Kordík, P. · ACM Transactions on Recommender Systems (2025)
  3. Downscaling climate projections to 1 km with single-image super resolutionKošťál, P., Kordík, P., & Podsztavek, O. · NeurIPS 2025 Workshop on Tackling Climate Change with Machine Learning (2025)
  4. Improving recommendation diversity and serendipity with an ontology-based algorithm for cold start environmentsKuznetsov, S., & Kordík, P. · International Journal of Data Science and Analytics, 20(2): 431–443 (2025)
  5. Reasoning-grounded natural language explanations for language modelsCahlík, V., Alves, R., & Kordík, P. · World Conference on Explainable Artificial Intelligence, pp. 3–18 (2025)
  6. The Future is Sparse: Embedding Compression for Scalable Retrieval in Recommender SystemsKasalický, P., Spišák, M., Vančura, V., Bohuněk, D., Alves, R., & Kordík, P. · Proceedings of the 19th ACM Conference on Recommender Systems, pp. 1099–1103 (2025)
  7. Bridging Global Language Models and Local Spatial Data: The JackDaw Approach to Context-Aware Agriculture and Rural PlanningCharvát, K., Berhgeim, R., Palma, R., Rynkiewicz, A. A., Botek, M., Kovalenko, A., Kordík, P., Horáková, Š., & Kollerová, M. · Proceedings of FedCSIS 2025, Annals of Computer Science and Information Systems 43, pp. 507–518 (2025)
  8. Recurrent Autoregressive Linear Model for Next-Basket RecommendationZmeškalová, T., Ledent, A., Spišák, M., Kordík, P., & Alves, R. · Proceedings of the 19th ACM Conference on Recommender Systems, pp. 1273–1278 (2025)
  9. Segment-Aware Analytics for Real-Time Editorial Support in Media GroupsSpišák, M., Alves, R., Kelleher, T., Sheppard, J., Fiedler, O., Kosovrasti, E., Vančura, V., Kasalický, P., & Kordík, P. · INRA 2025: 13th International Workshop on News Recommendation and Analytics @ RecSys 2025, CEUR-WS Vol-4056 (2025)
  10. Data-driven closure model selection for multiphase CFD via matrix completionHänsch, S., Sajdoková, A., Rabau, A., Rybář, V., Alves, R., & Kordík, P. · AI Thermal Fluids, 100019 (2025)
  11. Enhancing Fractional Gradient Descent with Learned OptimizersSobotka, J., Šimánek, P., & Kordík, P. · arXiv preprint arXiv:2510.18783 (2025)
  12. Active Recommendation for Email Outreach DynamicsŽid, Č., Alves, R., & Kordík, P. · Proceedings of the 34th ACM International Conference on Information and Knowledge Management, pp. 5540–5544 (2025)
Show 20 earlier papers (2010–2024)

2024

  1. beeFormer: Bridging the Gap Between Semantic and Interaction Similarity in Recommender SystemsVančura, V., Kordík, P., & Straka, M. · Proceedings of the 18th ACM Conference on Recommender Systems (2024)

2023

  1. Overcoming the Cold-Start Problem in Recommendation Systems with Ontologies and Knowledge GraphsKuznetsov, S., & Kordík, P. · European Conference on Advances in Databases and Information Systems, pp. 591-603 (2023)
  2. Personalised Recommendations and Profile Based Re-ranking Improve Distribution of Student OpportunitiesŽid, Č., Kordík, P., & Kuznetsov, S. · Computational Intelligence in Security for Information Systems Conference (2023)
  3. Bridging Offline-Online Evaluation with a Time-dependent and Popularity Bias-free Offline Metric for RecommendersKasalický, P., Alves, R., & Kordík, P. · 2nd Edition of EvalRS: A Rounded Evaluation of Recommender Systems - KDD Workshop, Long Beach, CA, USA (2023) Best Paper Award
  4. Decorelated Weight Initialization by BackpropagationKovalenko, A., & Kordík, P. · International Conference on Artificial Neural Networks, pp. 546-550 (2023)

2022

  1. Scalable linear shallow autoencoder for collaborative filteringVančura, V., Alves, R., Kasalický, P., & Kordík, P. · Proceedings of the 16th ACM Conference on Recommender Systems, pp. 604-609 (2022)
  2. Adapting the Size of Artificial Neural Networks Using Dynamic Auto-SizingCahlík, V., Kordík, P., & Čepek, M. · IEEE International Conference on Computer Sciences and Information Technologies (2022)
  3. Learning to Optimize with Dynamic Mode DecompositionŠimánek, P., Vašata, D., & Kordík, P. · International Joint Conference on Neural Networks, pp. 1-8 (2022)
  4. RepSys: Framework for Interactive Evaluation of Recommender SystemsŠafařík, J., Vančura, V., & Kordík, P. · Proceedings of the 16th ACM Conference on Recommender Systems, pp. 636-639 (2022)

2021

  1. Transfer learning based few-shot classification using optimal transport mapping from preprocessed latent space of backbone neural networkChobola, T., Vašata, D., & Kordík, P. · AAAI Workshop on Meta-Learning and MetaDL Challenge, pp. 29-37 (2021) 2nd Place Award
  2. Deep Variational Autoencoder with Shallow Parallel Path for Top-N Recommendation (VASP)Vančura, V., & Kordík, P. · International Conference on Artificial Neural Networks, pp. 138-149 (2021)
  3. Stratified Cross-Validation on Multiple ColumnsMotl, J., & Kordík, P. · IEEE 33rd International Conference on Tools with Artificial Intelligence, pp. 26-31 (2021)
  4. Novel Data Mining-based Age-at-death Estimation Model using Adult Pubic Symphysis 3D ScansBuk, Z., Štepanovský, M., Koterová, A., Velemínská, J., Brůžek, J., & Kordík, P. · Information Technologies – Applications and Theory, pp. 46-52 (2021)

2019

  1. Chameleon 2: an improved graph-based clustering algorithmBarton, T., Bruna, T., & Kordik, P. · ACM Transactions on Knowledge Discovery from Data (TKDD), Vol. 13(1), pp. 1-27 (2019)

2018

  1. Discovering predictive ensembles for transfer learning and meta-learningKordík, P., Černý, J., & Frýda, T. · Machine Learning, Vol. 107(1), pp. 177-207 (2018)

2016

  1. Neural turing machine for sequential learning of human mobility patternsTkačík, J., & Kordík, P. · International Joint Conference on Neural Networks (IJCNN), pp. 2790-2797 (2016)
  2. Reducing cold start problems in educational recommender systemsKuznetsov, S., Kordík, P., Řehořek, T., Dvořák, J., & Kroha, P. · International Joint Conference on Neural Networks (IJCNN), pp. 3143-3149 (2016)

2010-2012

  1. Selecting representative data setsBorovicka, T., Jirina, M. Jr., Kordík, P., & Jirina, M. · Advances in data mining knowledge discovery and applications 12, 43-70 (2012)
  2. The age at death assessment in a multi-ethnic sample of pelvic bones using nature-inspired data mining methodsBuk, Z., Kordik, P., Bruzek, J., Schmitt, A., & Snorek, M. · Forensic Science International 220 (1-3), 294.e1-294.e9 (2012)
  3. Meta-learning approach to neural network optimizationKordík, P., Koutník, J., Drchal, J., Kovářík, O., Čepek, M., & Šnorek, M. · Neural Networks, Vol. 23(4), pp. 568-582 (2010)

Work with me

If something on this page is close to what you do, get in touch. A few lines are enough; we can sort out the details later.

PhD in my group

Doctoral topics follow my research lines: recommendation and search, trustworthy AI agents and language models, AI for climate and science, and AI for learning. Experience from a company is an advantage.

Research and projects together

Joint papers, Horizon Europe and national proposals, and contract research where we have shown results: recommendation and search, language-model agents and their safety, machine learning for weather and climate, and AI in education.

Talks and lectures

Topics I know best: recommender systems and search in practice, AI agents and their safety (also for children), machine learning for weather and climate, AI in education, and how university research turns into companies.

Join one of my projects

Researchers, developers, designers and teachers are welcome in Tiny (AI for schools), p-books, SlAIdy, AutoResearch, colAIborate and EduMatch, whether the project is academic, non-profit or commercial. Tell me what you would like to do.

Help AI dětem grow

Teaching children about AI is important and still neglected. AI dětem works with Czech schools, and we want to scale it globally. Schools, funders, translators and partners abroad: let's talk.

Bachelor's or master's thesis

I supervise a limited number of theses, for independent students. A topic of your own is welcome if it builds on our research; it should have research potential and a result you can measure.

Get in touch

Name, e-mail and a few lines about what you have in mind are enough. I will reply and we can sort out the rest then.

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