Joel Kaasinen
Senior Consultant at Metosin
Helsinki, Finland
Summary
🤩
Rockstar🎓
Top SchoolJoel Kaasinen is a senior consultant and functional programmer based in Helsinki with 16 years of hands-on experience building robust back-end systems and bridging business and technology. He mentors teams, supports sales and customer relations, and practices full-stack Clojure development while actively contributing to open source projects like metosin/malli and the University of Helsinki Haskell MOOC. His background spans embedded and robotics software, machine learning, and systems work from Nokia to Zenrobotics, giving him a strong pragmatic foundation in C, C++, Java, Python and Linux tooling. Joel’s academic teaching experience in functional programming and type theory informs his clear technical writing and curriculum contributions to educational repos. Notably, he has improved data-spec and error-explaining tooling in malli and helped shape core data structures in the Carp language, showing a blend of language design insight and production-focused engineering.
16 years of coding experience
13 years of employment as a software developer
Ylioppilastutkinto, Ylioppilastutkinto at Päivölän kansanopistoMaster of Science (M.Sc.), Computer Science, Master of Science (M.Sc.), Computer Science at University of Helsinki
Stackoverflow
5,159reputation
314kreached
56answers
0questions
git
top-5%
shell
top-5%
haskell
top-5%
Github Skills (33)
algorithms10
static-typing10
schema-validation10
data-validation10
clojure-cli10
testing10
technical-writing10
data-structure10
functional10
clojure10
data-structures10
error-handling10
functional-programming10
haskell10
documentation10
Programming languages (10)
Github contributions (5)
moocfi/haskell-mooc
May 2020 - Jan 2023
Haskell MOOC University of Helsinki
Role in this project:
Technical Writer
Technical WriterContributions:1 review, 377 commits, 36 PRs in 2 years 9 months
Contributions summary:Joel's commits primarily involve updating and expanding the content of the Haskell MOOC, specifically focusing on the first part of the course. The changes include adding content, examples, and exercises related to topics like Haskell syntax, recursion, datatypes, type classes, and basic IO. The user's contributions aim to improve the clarity, structure, and completeness of the learning materials.
mooc-fighchaskellcabalservant
metosin/malli
Mar 2022 - Dec 2022
High-performance data-driven data specification library for Clojure/Script.
Role in this project:Back-end Developer
Back-end DeveloperContributions:56 reviews, 15 commits, 53 PRs in 9 months
Contributions summary:Joel primarily contributed to the `malli` library, focusing on enhancing its functionality and improving its usability. Their work involved adding new features such as `mu/keys`, `m/data-explainer`, and `m/explain-data` that improved data handling and error reporting. Additionally, the user refactored existing code to improve efficiency and maintainability, including moving functions to relevant modules and removing unnecessary local functions. The contributions also included extensive testing to ensure the reliability and correctness of the new features.
transformationdata-drivenvalidationgeneratorsclojurescript
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