Guillaume Ferry, Software Developer in Paris, France
Guillaume Ferry

Software Developer in Paris, France

Member since November 16, 2016
As an experienced machine learning practitioner (Kaggle expert), data engineer and architect, Guillaume builds artificial intelligence (AI) and data applications and systems for clients. He develops statistical models, ETL jobs, APIs, basic front-ends, and researches new solutions and approaches for algorithm scaling.
Guillaume is now available for hire




Paris, France



Preferred Environment

Linux, Python 3.6, SQL, Jupyter, AWS

The most amazing...

...thing I've done was to develop an optimization prototype for a Management Consulting company in partnership with MIT.


  • Freelance Data Engineer and Architect

    2018 - 2019
    Healthcare Company (via Toptal)
    • Set up the data lake architecture to host source data.
    • Connected the data lake to an IoT platform through API.
    • Wrote transformation and loading scripts for feeding an application database.
    Technologies: AWS Glue, AWS Lambda, Spark
  • Freelance Data Lab Data Scientist | Architect

    2018 - 2018
    Healthcare Company (via Toptal)
    • Set up the back-end architecture for operationalizing a machine-learning PoC to an MVP.
    • Developed the ETL for retrieving and updating public data sources.
    • Created a search engine API based on the Word2Vec model.
    Technologies: Python, Word2Vec, Gensim, Sklearn, Flask, AWS, PostgreSQL
  • Freelance Data Scientist

    2017 - 2018
    Credit Insurance Company (via Toptal)
    • Developed a data exploration with Python and Jupyter.
    • Set up machine learning models.
    Technologies: Python, Jupyter, Sklearn
  • Freelance Catnat Analytics Consultant

    2017 - 2017
    • Designed the data architecture.
    • Developed the ETL and data pipelines.
    • Worked on R development and optimization.
    Technologies: R, SQL Server
  • Manager | Data Scientist

    2015 - 2016
    A Global Management Consulting and Professional Services Company
    • Worked on a variety of jobs for a clearing bank.
    • Developed an optimization prototype in partnership with MIT.
    • Architected and modeled data for a new business service.
    • Developed a mobile payment application; involving data lake specifications coordination, data strategy definition, and report prototyping.
    Technologies: Python, CPLEX, Sklearn, SQL, Tableau
  • RTB Data Scientist

    2015 - 2015
    • Built predictive models.
    • Worked with machine learning.
    • Conducted AB testing in Python.
    Technologies: Python, SQL, Sklearn
  • Developer of Real-time Prediction of Train Delays

    2014 - 2014
    SNCF (French Railways) | R&D, Statistics, Econometrics, and Data-mining
    • Developed a Python prototype for real-time prediction of train delays—from the IT architecture to coding and integration.
    Technologies: Python, MySQL, Sklearn
  • Developer (Prototype Pushing Personalized Press Articles)

    2013 - 2014
    Ownpage | Full-year Scholar Project
    • Coded a multithreaded Java crawler, Lucene indexer, and retriever.
    • Installed and maintained the production environment.
    Technologies: Java, Multithread, Lucene, Ubuntu, JRuby on Rails, MySQL, Apache, Upstart Services
  • Transformation Program Analyst

    2011 - 2013
    Euler Hermes
    • Acted as the roll-out coordinator in Germany—involving project management, training, and technical/functional advising for one year.
    • Designed functional architecture (4 months).
    • Consulted on IT for a subsidiary roll-out (business need, functional specifications, parameters set-up); 10 months.
    • Reworked the business processes of contract management departments of the subsidiaries (Hamburg, London, Rome, Brussels, and Paris) with a Lean-Six Sigma approach; six months.
    Technologies: Excel, PowerPoint
  • Technical Business Analyst

    2007 - 2011
    BNP Paribas Cardif | Financial Back-Office
    • Process mapped, analyzed, and implemented improvements.
    • Developed dashboards and Excel, Access, and VBA tools.
    Technologies: VBA, Access, Excel, SQL
  • Developer | Process Mapper

    2007 - 2009
    BNP Paribas Cardif | IT Department
    • Process mapped and implemented indicators and controls for international subsidiaries to cover critical IT risks.
    Technologies: Mega
  • Auditor

    2007 - 2007
    CA CIB | Back-office
    • Audited for quality and regulatory compliance.
    • Developed an Access database for cross-analysis of risks vs controls.
    Technologies: Access, VBA


  • Kaggle Competitions Expert (Other amazing things)

    • A Facebook Challenge (IV) where I reached the top 7%.
    • Wikipedia Web Traffic Time Series Forecasting, reached the top 8%.

    Technologies: Python, SKlearn, TensorFlow

  • Python Machine Learning Prediction with a Flask REST API (Publication)
    Employing Python to make machine learning predictions can be a daunting task, especially if your goal is to create a real-time solution. However, Tensorflow and Scikit-Learn can significantly speed up implementation. In this article, Toptal Python Developer Guillaume Ferry outlines a simple architecture that should help you progress from a basic proof of concept to a minimal viable product without much hassle.


  • Languages

    Python, SQL, R, Java
  • Libraries/APIs

    Sklearn, Keras
  • Paradigms

    Data Science
  • Frameworks

  • Tools

    AWS Glue, Tableau
  • Platforms

    AWS EC2, AWS Lambda


  • Master of Science degree in Machine Learning, Big Data, and Statistics
    2013 - 2014
    Télécom ParisTech - Paris, France
  • Participated as an exchange student in Industrial Engineering
    2005 - 2006
    Concordia University - Montreal, QC, Canada
  • Engineer's degree in Industrial Engineering
    2002 - 2006
    Ecole Mines of Douai - Douai, France


  • Machine Learning
    Stanford University via Coursera

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