Yohan Graterol
CTO at Coinary LTD
Bogota, RAP (Especial) Central, Colombia
Summary
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Rockstar🎓
Top SchoolYohan Graterol is a seasoned technology leader and CTO with 13 years of experience building backend systems, open-source projects, and blockchain tooling from Bogotá, Colombia. As co-founder and former CEO of Callisto Network and current CTO at Coinary, he blends startup leadership with hands-on development in Python, Ethereum ecosystems, and developer tooling. He has a long track record contributing to notable open-source projects—maintaining MongoEngine, improving Vyper (a Pythonic EVM language), and extending MyEtherWallet to support multiple EVM-compatible chains—demonstrating both deep systems knowledge and protocol-level insight. Former Head of Engineering at Platzi, he pairs product-minded engineering management with practical expertise in test automation and code quality. An active Fedora contributor and package maintainer, he brings a community-first approach and rare cross-cutting experience across infrastructure, crypto wallets, and ORM libraries.
13 years of coding experience
8 years of employment as a software developer
Ingeniero de Computación Computación, Ingeniero de Computación Computación at Universidad José Antonio Páez
English, Spanish
Stackoverflow
603reputation
98kreached
32answers
0questions
Github Skills (35)
debug10
javascript10
docker10
vyper10
pytest10
python10
testing10
dockers10
mongodb-database10
orm10
ethereum10
blockchain10
automated-tests10
python-lib10
mongodb10
Programming languages (19)
Github contributions (5)
MongoEngine/mongoengine
Jan 2014 - Apr 2015
A Python Object-Document-Mapper for working with MongoDB
Role in this project:
Back-end Developer
Back-end DeveloperContributions:73 commits, 4 PRs, 1 push in 1 year 3 months
Contributions summary:Yohan primarily contributed to the `mongoengine/mongoengine` repository by implementing features and fixing bugs related to the core functionality of the object-document mapper. They enhanced image handling capabilities with progressive JPEG support and updated the changelog to reflect the changes. The user also addressed issues, such as fixing atomic updates for DictField, and resolved merge conflicts, demonstrating a focus on maintaining and improving the library's features.
mongodb-ormpythonmongodocument-mapperpython3
vyperlang/vyper
Jul 2017 - Aug 2017
Pythonic Smart Contract Language for the EVM
Role in this project:Back-end Developer & Test Automation Engineer
Back-end Developer & Test Automation EngineerContributions:14 commits, 6 PRs, 62 comments in 29 days
Contributions summary:Yohan primarily contributed to the Vyper smart contract language repository through code quality improvements and test suite enhancements. Their work includes PEP8 style formatting, removal of unnecessary imports, and the addition of a `Compiler` class object. They created and integrated functions to facilitate gas estimation within the testing framework, refactoring existing tests to leverage these features. This involved modifications to the testing setup and test cases, demonstrating a focus on code quality and automated testing.
pythonsmart-contractethereumcontractblockchain
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