Ricardo Rei | Unbabel, London, UK

About Me

I’m Ricardo Rei, a Senior Research Scientist at Unbabel leading research on multilingual Large Language Models. My work focuses on LLM evaluation, post-training techniques, and advancing machine translation capabilities across languages. I recently completed my PhD at Instituto Superior Técnico (IST), University of Lisbon, graduating with the distinction of Summa cum laude for my research on machine translation evaluation. My doctoral work was conducted through a collaborative program between Unbabel, IST, and Carnegie Mellon University (CMU), known as Multilingual AI Agents Assistants (MAIA).

Last update: 17-04-2025

Teaching & Mentorship:

Currently co-advise PhD students working on LLM evaluation, post-training, and culturally-informed AI agents.

José Pombal: Working on LLM evaluation and post-training. He is one of the main authors of Tower LLM.
Helena Wu: Developing Culturally-Informed AI Agent and Personae.

Recent News

• Jun 2025: I’ll be part of a panel dicussion at Massively Multilingual AI Conference 2025
• Apr 2025: 🎉 Received EAMT Best Thesis award!
• Apr 2025: Keynote at Globalization and Localization Association Annual Conference (GALA)
• Mar 2025: We are releasing EuroBERT models and paper!
• Dec 2024: We are releasing EuroLLM 9B supporting 35 languages!

Selected Publications * = equal contribution

WMT 2024

Tower v2: Unbabel-IST 2024 Submission for the General MT Shared Task

Ricardo Rei*, Jose Pombal*, Nuno M. Guerreiro*, João Alves*, Pedro Henrique Martins*, Patrick Fernandes, Helena Wu, Tania Vaz, Duarte Alves, Amin Farajian, Sweta Agrawal, Antonio Farinhas, José G. C. De Souza, André Martins

Ninth Conference on Machine Translation (WMT24), 2024.

PDF
ArXiv

EuroLLM: Multilingual language models for europe

Pedro Henrique Martins*, Patrick Fernandes*, João Alves*, Nuno M Guerreiro*, Ricardo Rei*, Duarte M Alves, José Pombal, Amin Farajian, Manuel Faysse, Mateusz Klimaszewski, Pierre Colombo, Barry Haddow, José GC De Souza, Alexandra Birch, André F.T. Martins

PDF Models
COLM 2024

TowerLLM: An Open Multilingual Large Language Model for Translation-Related Tasks

Duarte M. Alves*, José Pombal*, Nuno M. Guerreiro*, Pedro H. Martins, João Alves, Amin Farajian, Ben Peters, Ricardo Rei, Patrick Fernandes, Sweta Agrawal, Pierre Colombo, José G.C. de Souza, André F.T. Martins

First Conference on Language Modeling (COLM), 2024.

PDF Code
NAACL 22

Quality-Aware Decoding for Neural Machine Translation

Patrick Fernandes*, António Farinhas*, Ricardo Rei, José G. C. de Souza, Perez Ogayo, Graham Neubig, Andre Martins

Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (NAACL), 2022.

PDF Code Video
EMNLP 20

COMET: A Neural Framework for MT Evaluation

Ricardo Rei, Craig Stewart, Ana C Farinha, Alon Lavie

2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), 2023.

PDF Code Video

Past News

• Nov 2024: Keynote at NINTH CONFERENCE ON MACHINE TRANSLATION (WMT24)
• Nov 2024: Keynote at Sword AI Summit 24
• Oct 2024: 🏆 Tower v2 ranked first on the WMT General Translation Task,
• June 2024: Keynote at First International Workshop on Knowledge-Enhanced Machine Translation
• Feb 2024: We released 🗼 TowerLLM: An Open LLM for Translation-Related Tasks
• December 2023: 🏆 xCOMET got first place on the WMT 23 Metrics Shared Task,
• Oct 2023 : Paper accepted at WMT 23 (shared task paper)
• Oct 2023 : Paper accepted at EMNLP 2023 (findings)
• June 2023: Keynote at Machine Translation Marathon in the Americas,
• May 2023 : Our paper “The Inside Story” was accepted at ACL 2023 (main)
• Sep 2022 : Invited lecture at Fifteenth Machine Translation Marathon, Prague
• Aug 2022 : Led the winning submission to the WMT 2022 Shared Task on Quality Estimation held at EMNLP 2022
• Aug 2022 : Paper accepted at EMNLP 2022 (main)
• Aug 2022 : 🎉 Received EAMT 2022 Best paper award!
• May 2022 : For the next 3 months I’ll be visiting CMU!
• May 2022 : Paper accepted at EAMT 2022 (research track)
• Apr 2022 : Paper accepted at NAACL 2022 (main)
• Nov 2021 : Panel discussion on evaluation held at WMT
• Oct 2021 : Collaborated on the winning submission to the Eval4NLP Explainable Quality Estimation Shared Task held at EMNLP 2021
• Aug 2021 : Paper accepted at EMNLP 2021 (main)
• May 2021 : 2 papers accepted at ACL 2021 (one long and another demo)
• Sep 2020 : Paper accepted at EMNLP 2020 (main)
• Sep 2020 : Started my PhD at Instituto Superior Técnico, supervised by Luisa Coheur and Alon Lavie