Personal details

Leon S. - Remote data scientist

Leon S.

Data Scientist
Based in: 🇧🇷 Brazil
Timezone: Brasilia (UTC-3)

Summary

I'm a senior full-stack Developer, with 15+ years of experience. I've built systems for telecom, the department of motor vehicles, UN projects, and the government sector (ministry of education, army, attorney office, tax administration). I'm also a data scientist with 3+ years of experience working with R and Python with predictive models in production and papers published in international conferences.

I have 64+ jobs/sessions and 25 reviews, all five stars (check codementor.io/@leonsolon) at Codementor.

Main skills:

  • Languages: Java, Python, R, SQL, HTML, CSS, Javascript
  • Frameworks/Libs: Spring, Spring Boot, Bootstrap, Pandas, Dash, Plotly, Seaborn, TensorFlow, Numpy, Scikit-Learn, PyCaret

Client reviews from Codementor:

Sam Bravo - November 2020
Leon was the best help I have ever received. So patient, kind, and smart! Did not abandon me. Extremely reliable/communicative/and timely. Will get the job done! I will definitely go to him again in the future !

Michael Gloven - July 2020
excellent work, was able to resolve a complicated issue in short time

Msdek - June 2020
He does the work he is asked for. Cooperates, high-quality code. High knowledge of Java.

elbin zacharia mathew - June 2020
Best and professional in his works. Has a positive attitude and very helpful to rectify problems faced. I recommend him. Thank you for helping me out mate. Appreciate your patience.

Nuno Simões - May 2020
Fantastic understanding. Works very quickly, very friendly and sugests new ways to make projects that are very interesting. I will definitly hire him again.

Joel Chenoweth - May 2020
I've never tried this before but Leon really helped a lot. He was timely, fast... a real pro!

Navid - May 2020
Leon is honest, friendly, and a skillful coder in Python (data science). More importantly he is a moral human being! Will definitely come back again!

Da Yin - May 2020
Leon is very progressional and very kind in helping me with. I highly recommend Leon! Thank you Leon.

Caroline Alexander - May 2020
Leon was SO helpful in getting my R code to work. I am very thankful!!

Work Experience

Data Scientist and Backend Developer
Secretariat of Federal Revenue of Brazil | Jun 2006 - Present
Python
Java
Machine Learning
Data Science
RStudio

I'm a Tax Auditor working as Data Scientist and Backend Python and Java Developer building predictive models on tax refund claims and taxpayer compliance risk.

Responsibilities:

ï‚· Create and deploy predictive models for tax fraud detection and prevention

ï‚· Create and deploy ML models of image classification (post office taxpayer warnings)

ï‚· Data mining for taxpayer selection for audit

Education

University of Brasilia
Msc・Applied Computing
Aug 2014 - Jun 2016

Personal Projects

Predictive Models on Tax Refund ClaimsIconOpenNewWindows
2015
Python
R
Machine Learning
One of the main goals of every tax administration is safeguarding tax justice. For that matter, accurate taxpayers’ auditing selection plays an important role. Current scenario of economic recession, budget cuts and tax professionals’ hiring difficulty combined with growth of both population and number of enterprises presents the necessity of a more efficiently approach from tax administration in order to meet its objectives. The present work intends to show how data mining techniques usage helps better understand the profile of non compliant tax payers who claim for tax refunds. Moreover, we present results on the adoption of predictive models towards selection improvement of those who claims that are more likely to be rejected in Federal Revenue of Brazil (RFB). Preliminary results shows that this approach is an efficient way for selecting tax payers rather than not using it.

Certifications & Awards

10th place MeLi Data Challenge
Mercado Libre | Sep 2021