Francesco Fabbri

Francesco Fabbri

Senior Research Scientist · Spotify · Barcelona

My research is on representation learning for personalization — currently focused on generative models, LLM agents, and LLM-as-a-Judge evaluation. Previously, PhD at UPF Barcelona on algorithmic bias in graph-based recommenders.

NOW

Currently focused on personalized LLM-as-a-Judge and judge-guided self-improvement for recommender systems at Spotify. Bridging the gap between subjective product quality and scalable, reliable evaluation.

Timeline
Career milestones, flagship papers, and invited talks — most recent at the top.
Apr 2026
CareerPromoted to Senior Research Scientist at Spotify.
Sep 2025
Publication RecSys '25
Prompt-to-Slate: Diffusion Models for Prompt-Conditioned Slate Generation

Generating coherent recommendation slates with prompt-conditioned diffusion. Moves recommendation from ranking-and-cut to learned slate generation.

Generative AI & LLM-Judge
Sep 2025
Publication RecSys '25 · LBR
Profile-aware LLM-as-a-Judge for Podcasts: A Better Middle Ground Between Offline Metrics and A/B Tests

A scalable, calibrated LLM judge that incorporates user profile context — a better middle ground between offline metrics and A/B tests for evaluating recommendations.

Generative AI & LLM-Judge
May 2025
Talk Invited keynote at UPF University · Barcelona.
Dec 2024
Publication AAAI '25 · AI for Social Impact
IOHunter: Graph Foundation Model to Uncover Online Information Operations

Cross-platform graph foundation model that detects coordinated inauthentic behavior — transferable across networks without per-platform retraining.

Responsible AI
Aug 2024
Talk Mentor & panelist at KDD '24 Doctoral Symposium.
May 2024
Publication theWebConf '24 · oral · lead author
Personalized Audiobook Recommendations at Spotify Through Graph Neural Networks

First cross-content GNN recommender for audiobook discovery. Co-listening graph design with LLM content representations and inductive item coverage.

Graph Recommendation
May 2024
Publication theWebConf '24
Towards Graph Foundation Models for Personalization

Position paper laying out what graph foundation models could look like for the personalization problem at industrial scale.

Graph Recommendation
Apr 2024
Talk Invited keynote · Graph Foundation Model for Personalization at IRonGraphs · ECIR '24.
Sep 2022
CareerPhD defended (cum laude) at UPF Barcelona · joined Spotify as Research Scientist.
Apr 2022
★ Best Paper · theWebConf '22
Rewiring What-to-Watch-Next Recommendations to Reduce Radicalization Pathways

A minimal-edit graph rewiring method that shortens radicalization pathways in video recommenders — without retraining the underlying model.

Responsible AI
2018
StartBegan PhD at UPF Barcelona with Francesco Bonchi and Carlos Castillo — algorithmic bias in graph-based recommenders.