Aymen Jaffry, Machine Learning Developer in Paris, France
Aymen Jaffry

Machine Learning Developer in Paris, France

Member since May 23, 2014
Aymen has worked for 6+ years as a data scientist, machine learning engineer, and consultant. He has worked in many industries, including finance, advertising, and online marketplaces. He greatly enjoys using machine learning and statistics to build state-of-the-art and efficient solutions. He holds an M.S. in Computational Engineering from Harvard University and a Master in Applied/Theoretical Mathematics from Ecole Centrale Paris.
Aymen is now available for hire


  • Yieldmo
    Models, Reinforcement Learning, Sklearn, SQL, Java, Python
  • Yieldmo
    Models, Reinforcement Learning, Sklearn, SQL, Java, Python
  • Catalant Technologies
    Graph Theory, Recommendation Systems, SQL, R, Python



Paris, France



Preferred Environment

Git, Atom, Jupyter, Python, OS X

The most amazing...

...thing I've built is a system using machine learning and statistics to predict 911 calls at the street level in the Boston area.


  • Machine Learning Consultant

    2016 - 2018
    • Developed an innovative classification algorithm, using online learning, to predict the advertisers’ conversion rates and automate bidding strategies.
    Technologies: Models, Reinforcement Learning, Sklearn, SQL, Java, Python
  • Data Scientist, Ad Serving Team

    2014 - 2016
    • Worked on display advertising, applying machine learning and reinforcement learning techniques to the problem of predicting click-through-rate.
    • Implemented a dynamic A/B testing platform that allowed thousands of A/B tests to run in parallel.
    • Used Bayesian Statistics and Thompson Sampling to redesign second-price auction rules and A/B testing decisioning.
    Technologies: Models, Reinforcement Learning, Sklearn, SQL, Java, Python
  • Machine Learning Consultant

    2013 - 2014
    Catalant Technologies
    • Built the first version of the matching engine from scratch using graph theory. This system recommends newly posted projects to MBA students on the platform and vice-versa.
    • Ran market analysis to identify lags between offer (projects) and demand (MBA students' expertises).
    Technologies: Graph Theory, Recommendation Systems, SQL, R, Python
  • Consultant in the Statistical Learning Team

    2011 - 2012
    • Developed a system in R recommending the best marketing means to reach each new customer on the website.
    • Conducted analysis to build customer groups using unsupervised and supervised learning techniques.
    Technologies: Clustering, Principal Component Analysis (PCA), Unsupervised Learning, Sklearn, Python, R
  • Assistant Trader and Structurer

    2010 - 2011
    UBS Investment Bank
    • Built a prototype tool that dynamically rebuilt a collateral portfolio using the risk of default analysis.
    • Assisted the secured funding team in creating new products by running forecast tests and coming up with.
    • Completed ROI and value propositions.
    • Priced primary/secondary quotes and hedged currency strategies.
    Technologies: Time Series Analysis, Visual Basic for Applications (VBA), R
  • Assistant Researcher

    2010 - 2010
    Cornell University, CFEM
    • Implemented a multi-agent system based on Ask/Bid and PnL data analysis simulating a stable financial market.
    • Worked under the supervision of Dr. Sasha Stoikov, Head of Research at CFEM.
    Technologies: Reinforcement Learning, C++, Java


  • Languages

    SQL, Python, Java, R, Visual Basic for Applications (VBA), C++, J
  • Libraries/APIs

    Sklearn, Scikit-learn, Pandas, Matplotlib, Spark ML, TensorFlow, Keras, REST APIs
  • Tools

    Jupyter, IPython, Git, Apache Airflow, Atom
  • Paradigms

    Data Science, Object-oriented Programming (OOP)
  • Platforms

    Eclipse, MacOS, Linux, Docker, OS X
  • Storage

    MySQL, AWS S3
  • Other

    A/B Testing, Mathematics, Analytics, Big Data, Bayesian Statistics, Advertising, Machine Learning, Vowpal Wabbit, Google BigQuery, Unsupervised Learning, Deep Learning, Natural Language Processing (NLP), Reinforcement Learning, Finance, Models, Recommendation Systems, Graph Theory, Principal Component Analysis (PCA), Clustering, Time Series Analysis
  • Frameworks

    Apache Spark


  • Master of Science degree in Computational Science and Engineering
    2013 - 2014
    Harvard University - Massachusetts
  • Master's degree in Applied and Theoretical Mathematics
    2009 - 2013
    Ecole Centrale Paris - Paris, France
  • Bachelor of Science degree in Mathematics, Physics
    2006 - 2009
    Marcelin Berthelot Preparatory Classes - Paris, France

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