Simeon Visser
Software Developer at Channable
London, England, United Kingdom
Summary
🤩
Rockstar🎓
Top SchoolSimeon Visser is a seasoned software developer with 16 years of experience building backend systems and integrations across e-commerce, supply chain, and web platforms, currently based in London and working at Channable. He has deep Python expertise—contributing to widely used OSS like python-json-logger and voluptuous where he improved compatibility, validation features, and cross-version support—showing an attention to robust, production-ready libraries. His career spans fast-paced startups and enterprise environments (Rangespan/Google, Ometria), delivering systems for order fulfillment, API integrations, pricing logic and operational tooling. Simeon pairs practical engineering with academic rigor (cum laude BSc and MSc in Agent Technology) and a background in teaching, which helps him explain complex technical issues clearly and drive improvements across teams.
16 years of coding experience
7 years of employment as a software developer
Bachelor of Science, Computer Science, With honor (cum laude, GPA 4.00), Bachelor of Science, Computer Science, With honor (cum laude, GPA 4.00) at Utrecht University
English, Dutch
Stackoverflow
120,626reputation
16.0mreached
1,242answers
2questions
pandas
top-1%
encoding
top-5%
virtualenv
top-5%
permutation
top-5%
oop
top-1%
dictionary
top-5%
Github Skills (63)
oop10
unit-testing10
json10
datetime10
data-validation10
python10
django10
testing10
pandas10
java10
dataframe10
integer10
rest10
python-requests10
mocking10
Programming languages (18)
Github contributions (5)
alecthomas/voluptuous
Oct 2014 - Jul 2019
CONTRIBUTIONS ONLY: Voluptuous, despite the name, is a Python data validation library.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:27 commits, 21 PRs, 4 pushes in 4 years 9 months
Contributions summary:Simeon made significant contributions to the `voluptuous` library, primarily focused on enhancing data validation capabilities. Their work included fixing Python 3 compatibility issues, adding new validators for datetime strings, and implementing support for sets and frozensets. Furthermore, the user addressed bugs, corrected typos, and improved the codebase by removing unused imports and refactoring code. They also worked on the test suite.
pythonvalidationvalidation-librarypython-datapythonic
madzak/python-json-logger
Aug 2014 - Jun 2018
Json Formatter for the standard python logger
Role in this project:Backend Developer
Backend DeveloperContributions:1 review, 8 commits, 7 comments in 3 years 10 months
Contributions summary:Simeon primarily contributed to the core functionality of the `python-json-logger` project. They implemented features such as customizing the JSON dictionary and allowing modification of the log record. Furthermore, the user updated the project to support multiple Python versions, including fixing compatibility issues and removing support for outdated versions. Their work focused on refining the library's features and ensuring its compatibility across different Python environments.
pythonjson-formatterstandard-pythonloggerlogging
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