Tatu Ylonen
PhD Student at Clausal Computing
Helsinki, Finland
Summary
👤
Senior🎓
Top SchoolTatu Ylonen is a cybersecurity and language-technology researcher and serial founder based in Helsinki, with roughly eight years of experience focused on advanced text understanding and knowledge representation alongside a long entrepreneurial track record. Best known as the original author of SSH—a tool that evolved into OpenSSH and broad industry standards—he has repeatedly turned research-grade ideas into widely deployed, production security solutions. He founded and led multiple companies (including SSH Communications Security and Clausal Computing), drove an IPO without venture capital, and holds ~30 patents related to AI and NLU. As a PhD student at the University of Helsinki he researches semantic parsing and discourse-level understanding while contributing pragmatic engineering to open-source projects like Wiktextract, improving multilingual lexicographic data extraction. Comfortable oscillating between low-level engineering (protocols, file systems, recovery) and high-level AI research, he combines deep systems instincts with a talent for turning intellectual property into commercial products. A less obvious strength is his history of shipping foundational infrastructure—database and recovery techniques—that quietly underpin many modern storage systems.
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 (13)
data-extraction10
wikitext10
python10
natural-language-processing9
nlp9
documentation8
pty6
rust6
amazon-ec26
amazon-web-services6
unix6
signal6
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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