Juan Manuel Ortiz de Zarate, Developer in Ciudad de Buenos Aires, Buenos Aires, Argentina
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Juan Manuel Ortiz de Zarate

Verified Expert  in Engineering

Data Scientist and Developer

Ciudad de Buenos Aires, Buenos Aires, Argentina
Toptal Member Since
November 6, 2019

Currently, Juan is a PhD candidate at the University of Buenos Aires, researching the subjects of AI, NLP, and social networks. He has over a decade of professional development experience under his belt. For the last few years, he’s been immersing himself in various types of data science projects and loving every minute of it. Juan relishes taking on data problems, building prediction models, and learning state-of-the-art techniques.



Preferred Environment

RStudio, Jupyter Notebook

The most amazing...

...thing I've coded is a an entire web app to monitor social networks. It has a back end in R for statistics and a PHP front end.

Work Experience

Chief Developer

2022 - PRESENT
P36 Labs
  • Developed a mobile app to negotiate football contracts. The app was very similar to Whatsapp but with the possibility of attaching contracts to chats, creating the terms, voting them, generating the contract text through GPT, and finally signing it.
  • Led the development team composed of me, a senior programmer, a junior programmer, and a tester.
  • Developed the AI feature to write the contract based on the terms voted and the language of the club hiring the player.
  • Managed the process of uploading the app to the Play Store, App Store, and Amazon server.
  • Charged with evaluating, selecting, and contracting external services to mailing, hosting, signing, database, and more.
  • Managed the relationship with the client to define the features, UX, UI, and timesheet.
Technologies: Artificial Intelligence (AI), OpenAI GPT-3 API, OpenAI GPT-4 API, Generative Pre-trained Transformers (GPT), Generative Pre-trained Transformer 3 (GPT-3), React Native, Node.js, MongoDB, Amazon Web Services (AWS)

Senior Data Scientist

2022 - PRESENT
  • Managed and supervised external students in their research.
  • Managed a different kind of research project with internal and external members.
  • Interviewed external collaborators and consultants to hire for specific projects and technical works.
Technologies: Artificial Intelligence (AI), Big Data, Natural Language Processing (NLP), Generative Pre-trained Transformers (GPT), Team Management, Hiring, Data Analysis, Web Scraping

Ph.D. Student Researcher

2017 - PRESENT
Universidad de Buenos Aires
  • Created new techniques to analyze discussions on social networks with R and Python.
  • Predicted movie reviews using the IMDB database with R.
  • Predicted implication clauses with NLP through Python models.
  • Developed new techniques to predict controversy with NLP techniques on social networks with R and Python.
  • Created new techniques to graph clusters with NLP techniques on social networks with Python and R.
Technologies: R, Python, Web Scraping

Freelance Data Scientist Advisor

2016 - PRESENT
Massomedia S.A.
  • Predicted presidential votes via telephone surveys using Python.
  • Analyzed several discussions on Twitter and Facebook using R.
  • Developed a web app using R, PHP, and MySQL to monitor social networks and media.
  • Built a product with Python that could analyze telephone surveys about product sales.
  • Presented the results, conclusions, and explanations for each task to the client.
Technologies: Python, R, Web Scraping

R Specialist

2023 - 2023
Beryl Capital Management LLC
  • Configured and installed a script to download and analyze data from brokers.
  • Repaired broken R libraries to fix the financial script.
  • Connected to the client's computer and chatted in real-time to test the script and apply all the fixes.
Technologies: R, RStudio, SharePoint, Financial Data, Stock Market, Bloomberg, Bloomberg Terminal, Bloomberg API

Front-end Developer

2022 - 2022
Nixtla Inc.
  • Developed new and custom plugins in TypeScript for JupyterLab.
  • Researched JupyterLab documentation to understand how to create new features.
  • Documented the creation of the new features and how they can be extended and installed in new environments.
Technologies: CSS, TypeScript, Front-end, Jupyter, Jupyter Notebook, Data Science, Forecasting, JupyterLab

Technical Editor

2021 - 2022
  • Corrected and edited technical articles about the latest technologies implementations.
  • Tested technological implementations described in the articles.
  • Evaluated writers' applications from all over the world for the company writers program.
Technologies: Python 3, PHP, Technical Writing, Writing & Editing, Auth0, Authentication, Authorization

Head Teaching Assistant

2020 - 2022
University of Buenos Aires
  • Acted as the head teaching assistant at Data Organization subject. In this subject, we try to introduce students to data science. This subject is part of the mandatory career plan for informatics engineering.
  • Designed all of the subject content together with another professor. Due to the COVID-19 lockdown, all of the online classes (in Spanish) are available on YouTube; if you would like to view them, contact me for the link.
  • Taught half of the theoric classes and half of the practical lessons. I also have to coordinate the teachers of the practical lessons and prepare and correct the final exams and practical works.
  • Designed the final test and the practical work that students must be approved to complete the subject.
Technologies: University Teaching, Data Science, Education, Machine Learning

Data Scientist

2021 - 2021
Carrie Beam Consulting
  • Created new functionalities in R to give a graph of financial relations suggesting new unions that improved trade between the actors.
  • Optimized algorithms on graphs so that they can work on large data sets.
  • Found bugs in existing R code and suggested better ones.
Technologies: Graphs, igraph, R, Networks, Computer Science

Teaching Assistant

2020 - 2021
Universidad Católica Argentina
  • Composed practical lessons for the Data Science class.
  • Corrected exams and practical homework for the Data Science subject.
  • Tutored and answered questions from students in the Data Science topics.
  • Explained machine learning techniques, regularizations methods, feature extraction and selection, data visualization methods, and more tasks related to data science.
Technologies: Data Science

Statistical Developer

2020 - 2020
Decentral Park Advisors LLC
  • Predicted Bitcoin 1D, 3D, and 7D returns with multinomial regressions and generalized additive models (GAMs).
  • Predicted Bitcoin 1D, 3D, and 7D positive or negative values through classification models as randomForest, XGBoost, and Bagging.
  • Reported the results through Jupyter Notebooks and R Shiny dynamic graphs.
Technologies: RStudio Shiny, R, Jupyter, Matplotlib, Pandas, Scikit-learn, Python

Data Analyst

2020 - 2020
LL Media, LLC
  • Standardized multiple information sources about leads using Python and Pandas.
  • Scored the performance of each source over different kinds of campaigns using Python, Pandas, and Matplotlib.
  • Predicted good leads by demographic data using machine learning classifiers scikit-learn.
  • Predicted bad leads by demographic data using machine learning classifiers scikit-learn.
  • Analyzed lead data to find simple correlations between good and bad lead performance.
Technologies: Matplotlib, Pandas, Scikit-learn, Python, Data Engineering

Teaching Assistant

2017 - 2018
Universidad de Buenos Aires
  • Composed practical lessons for the Computer Structures 1 class.
  • Corrected exams and practical homework for the Computer Structures 1 class.
  • Tutored and answered questions from students in the Computer Structures 1 class.
Technologies: Structure, Computer

Teaching Assistant

2016 - 2017
Universidad de Buenos Aires
  • Composed and gave practical lessons for the Network Theory class.
  • Corrected exams and homework for the Network Theory class.
  • Tutored and answered questions from students in the Network Theory class.
Technologies: Network Theory

Senior Full-stack Developer

2014 - 2015
  • Developed and maintained a system for journalists, which allowed them to write different types of notes and publish them on the news site.
  • Built and maintained a system to administrate the advertisement money.
  • Developed a REST API to connect with other media news sites.
Technologies: JavaScript, MySQL, PHP, Back-end

Senior Full-stack Developer

2010 - 2014
  • Built and maintained a system for call center assistance.
  • Developed and maintained features to communicate with the STB Systems and reset them.
  • Constructed and supported a dynamic decision tree to give the best answers to clients based on their specific problems and configurations.
  • Created and maintained an internal ticket system to organize tasks and assign them to different teams.
Technologies: jQuery, JavaScript, SQL, PHP, Back-end, Front-end

Principal Developer

2008 - 2010
  • Developed the company's administrative system.
  • Built a system to administer technique services.
  • Maintained the stock system.
  • Implemented a system to print digital photos from a Kodak machine.
  • Developed the company's financial system.
Technologies: JavaScript, MySQL, PHP

Data scientist at Fundar

I am a data scientist researcher at Fundar, where Fundar is an organization dedicated to studying, researching, and designing public policies focused on developing a sustainable and inclusive Argentina and there I have worked for different government dependencies, such as the Ministry of Tourism, the presidential secretary, and more. Also, I had to direct research scholarships that the foundation grants to students from different universities.

Professor of Data Science at University of Buenos Aires

I designed all of the subject content together with another professor.
I was responsible for giving theoretical and practical classes, correcting and designing midterms, and taking final tests. Due to the COVID-19 lockdown, all of the online classes (in Spanish) are available on YouTube; if you would like to view them, contact me for the link.

Technical Editor

I corrected and reviewed technical articles that different authors write for the Auth0 technology blog and the subject of the articles includes various fields: machine learning, security, developing frameworks, design patterns, and more.
I should also test the applications or code the authors develop in the article to see if they were well designed and implemented.

Social Network Analysis in R and Gephi: Digging Into Twitter

In this article, I show how to make a social network analysis using the Twitter API, R, and Gephi. By downloading a specific conversation, I build the social graph, plot it through a meaningful layout, and identify its principal communities.

Understanding Twitter Dynamics With R and Gephi: Text Analysis and Centrality

In this second article, I applied centrality measures to detect the principal actors of the discussion and natural language processing techniques to understand what they are talking about in each community.

Ensemble Methods: The Kaggle Machine Learning Champion

Two heads are better than one. This proverb describes the concept behind ensemble methods in machine learning. In this article, I examine why ensembles dominate ML competitions and what makes them so powerful.

A Glimpse Into the Future of Data Science

Data science is changing the world, it is at the heart of the fourth technological revolution. But how do we get here? How is the world changing? What else does this future hold?
In this article, I introduce the irruption of data science in our life, how we get here, some representative cases, and where we are going.

10 Best Data Science Development Frameworks to Use in 2021

In a world where data is more valuable than oil, the demand for data scientists and analysts is skyrocketing and in this article, I present the best tools for tapping into these data reserves. Hands down, Python is the clear choice for any aspiring developer trying to break into the field of data analysis.

Predicting Presidential Elections Through Surveys

Through telephone surveys, I predicted the votes of undecided voters.
I detected to which political cluster the undecided persons were close using clustering and machine learning techniques. With that information, I could predict with high accuracy their vote.

Application to Monitor Social Networks

I developed, on my own, an entire application to monitor social networks like Instagram, Facebook, and Twitter. It has statistics about any public account needed and sends messages/alarms to the client through a telegram if something important is happening.

It has a back end in R to download information, process it, and calculate statistics and a PHP front end to show the data. I also used C to manage sessions, create, delete, modify searches, and more.

Stars Realigned: Improving the IMDb Rating System

IMDb ratings have genre bias: Dramas tend to score higher, for example. Is there a way to remove such biases and discover what makes a movie unique?

In this article, I show you how to refine IMDb scores and create a better ranking system through data science and machine learning techniques.

Predicting Kindle Reviews

In this project, I have developed a natural language processing (NLP) model using fastText. The purpose of this model is to predict if a Kindle review will be positive, neutral, or negative based on the text written by the users.

Hiring Data Scientists — Best Practices and Job Description Template

Hiring an IT candidate is one of the hardest tasks that human resource professionals have to accomplish. Demand for IT professionals is greater than available individuals on the market, which produces competition between companies for the scarcely qualified developers.
In this article, I advise you on how to improve your candidates' research and hire the best profiles for your team.
2017 - 2022

Ph.D. Degree (in Progress) in Computer Science

Universidad de Buenos Aires - Buenos Aires, Argentina

2010 - 2016

Master's Degree in Computer Science

Universidad de Buenos Aires - Buenos Aires, Argentina


Generative AI with Large Language Models



LangChain: Chat with Your Data



ChatGPT Prompt Engineering for Developers



Deep Learning



Improving Deep Neural Networks: Hyperparameter Tuning, Regularization and Optimization



Laboratory of Machine Learning

ITBA | Instituto Tecnológico de Buenos Aires


igraph, Scikit-learn, Matplotlib, Pandas, Keras, Ggplot2, NumPy, jQuery, Caret, TensorFlow, Bloomberg API, Node.js


Dplyr, Seaborn, Jupyter, Auth0, Bloomberg, ChatGPT


RStudio Shiny, CodeIgniter, .NET, React Native


Data Science, Test-driven Development (TDD)


PHP 7, Python, Python 3, R, SQL, JavaScript, CSS, PHP, TypeScript, HTML


RStudio, Jupyter Notebook, Linux, WordPress, Oracle, Gephi, SharePoint, Bloomberg Terminal, Kindle, Amazon Web Services (AWS)


MySQL, MongoDB


Data Visualization, Charts, Social Networks, Social Network Analysis, Visualization Tools, OOP Designs, Machine Learning, Data Analytics, Data Analysis, Big Data, Natural Language Processing (NLP), Artificial Intelligence (AI), OpenAI GPT-3 API, OpenAI GPT-4 API, Leads, Data Preprocessing, Education, Time Series, Time Series Analysis, Clustering, Statistics, Code Review, Source Code Review, Team Management, Interviewing, Generative Pre-trained Transformers (GPT), Deep Learning, Generative Pre-trained Transformer 3 (GPT-3), Large Language Models (LLMs), Cloud, Feature Analysis, Web Scraping, Network Theory, Computer, Structure, University Teaching, Stock Market, Stock Trading, Graphs, Networks, Computer Science, Writing & Editing, Hiring, Technical Writing, Authentication, Authorization, Back-end, Front-end, Data Engineering, Forecasting, JupyterLab, Blogging, Blog Posting, Technical Hiring, Financial Data, fastText, Neural Networks, Deep Neural Networks, LangChain, Data Scientist, Diffusion-based AI Models, Generative Adversarial Networks (GANs), ChatGPT Prompts

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