Yoan Russac

Machine Learning Researcher



I am a Machine Learning Researcher. Previously, I was a Machine Learning Researcher within Twitter Cortex where I was part of the Recommender System team. I worked mostly on the Heavy Ranker used for ranking the different tweets on the Twitter timeline. I hold a PhD in Machine Learning from Ecole Normale Supérieure in the Center for Sciences of Data where I was lucky to be supervised by Olivier Cappé and Aurélien Garivier. My research interests include sequential learning with partial information feedback (more precisely bandits models) and more recently Deep Learning. The main objective of my PhD was to improve decision-making in uncertain and dynamic environments. In particular, I have worked on passively forgetting strategies that are well-suited for non-stationary environments and non-parametric algorithms.


  • Bandits
  • Machine Learning
  • Reinforcement Learning
  • Deep Learning


  • PhD in Machine Learning, 2018-2022

    Ecole Normale Supérieure

  • MVA Master Degree, 2017-2018

    ENS-Paris Saclay

  • MSc in Statistics and Data Science, 2015-2018

    ENSAE- Institut Polytechnique de Paris



Machine Learning Researcher


Mar 2022 – Apr 2023 London, UK

Machine Learning Engineer Intern


Jun 2021 – Aug 2021 London, UK

Applied Scientist Intern


Jun 2018 – Nov 2018 Berlin, Germany
Research on non-stationarity and bandits.

Machine Learning Researcher Intern


Jun 2017 – Sep 2017 Brussels, Belgium
Research on fraud detection using Word2Vec embeddings.


  • 45 rue d'Ulm, Paris, 75005, France