Tatu Ylonen
PhD Student at University of Helsinki
Helsinki, Finland
Summary
👤
Senior🎓
Top SchoolTatu Ylonen is a seasoned software leader and researcher, best known as the original author of SSH and a driving force behind OpenSSH and modern cybersecurity standards. Based in Helsinki, Finland, he is currently a PhD student at the University of Helsinki, exploring text understanding, discourse, and knowledge representation, while contributing to AI and language technology research. He has founded and led multiple ventures, including Clausal Computing and SSH Communications Security, where he steered growth to an IPO and built enterprise-grade SSH key management and access control solutions. An active open-source contributor, he has shaped projects like Wiktextract as a back-end developer and documentation specialist, enhancing multilingual data extraction and data cleaning. He holds MSc and Licentiate degrees from Aalto University, reflecting a long-standing ability to translate research into scalable, practical technology. His career spans academia, entrepreneurship, and hands-on engineering, merging cybersecurity, NLP, and data engineering to address complex real-world challenges.
8 years of coding experience
21 years of employment as a software developer
Licentiate degree, Computer Science/Cognitive Science, Licentiate degree, Computer Science/Cognitive Science at Aalto University
Stackoverflow
46reputation
9kreached
3answers
0questions
Github Skills (14)
data-extraction10
wikitext10
python10
natural-language-processing9
nlp9
documentations8
documentation8
pty6
rust6
signals6
amazon-ec26
amazon-web-services6
unix6
ssh6
Programming languages (5)
Github contributions (5)
tatuylonen/wiktextract
Oct 2018 - Nov 2022
Wiktionary dump file parser and multilingual data extractor
Role in this project:
Back-end Developer & Technical Documentation Specialist
Back-end Developer & Technical Documentation SpecialistContributions:920 commits, 11 PRs, 757 pushes in 4 years 1 month
Contributions summary:Tatu primarily focused on improving the functionality of the Wiktextract project by making changes to the code. This included modifying existing features, such as implementing parsing of senses from second-level numbered lists, extracting etymology data, and extracting translations. They also made improvements to the documentation of the project. Further, the user made changes to the existing code, such as renaming fields, and improved cleaning of the data.
extractionpythonwiktionaryparserparsing
tatuylonen/wikitextprocessor
Oct 2020 - Oct 2022
Python package for WikiMedia dump processing (Wiktionary, Wikipedia etc). Wikitext parsing, template expansion, Lua module execution. For data extraction, bulk syntax checking, error detection, and offline formatting.
Contributions:2 reviews, 294 commits, 3 PRs in 2 years
extractionpythonwiktionaryexpansiontemplate-parsing
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