Joona Kiiski
Senior Staff Software Engineer at Zoox Inc.
Cupertino, California, United States
Summary
🤩
Rockstar🎓
Top SchoolJoona Kiiski is a Senior Staff Software Engineer with 17 years of experience, currently building autonomous vehicle software at Zoox from his base in Cupertino. He brings deep systems and performance expertise—reflected in notable open-source work optimizing the Stockfish chess engine in JavaScript, where he compressed transposition table entries and tuned search loops for efficiency. With a Master’s in Physics and a background teaching mathematics and physics, he combines rigorous analytical thinking with pragmatic engineering. Joona’s career spans consultancy and long-term platform work, and he’s known for squeezing more performance out of complex algorithms rather than relying on brute-force resources.
17 years of coding experience
4 years of employment as a software developer
Master, Physics, Master, Physics at University of Jyvaskyla
Finnish, English, German, Swedish
Stackoverflow
1reputation
0reached
0answers
0questions
Github Skills (10)
algorithm10
data-structures10
algorithms10
c-language10
cprogramming-language10
performance-optimization10
data-structure10
chess-engine10
software-design9
chess9
Programming languages (4)
Github contributions (5)
mcostalba/Stockfish
Apr 2009 - Jul 2017
UCI chess engine
Role in this project:
Back-end Developer
Back-end DeveloperContributions:336 commits, 2 PRs, 14 comments in 8 years 4 months
Contributions summary:The user, Marco Costalba, primarily worked on the core engine logic, focusing on improving the chess engine's search capabilities. Their contributions include implementing dynamic aspiration search strategies and improving the handling of specific game states and scenarios, such as those involving time constraints or specific piece configurations. Additionally, they addressed several bugs, optimizing the code for performance and robustness within the context of the Stockfish chess engine.
chess-engineuci-chess-enginemachine-learninguci
nmrugg/stockfish.js
Jun 2014 - Dec 2014
The Stockfish chess engine in Javascript
Role in this project:Back-end Developer & Performance Engineer
Back-end Developer & Performance EngineerContributions:8 commits in 5 months
Contributions summary:Joona focused on optimizing the performance of the Stockfish chess engine in Javascript. Their contributions primarily involve refactoring and improving the efficiency of core components, specifically related to the transposition table (TT) and search algorithms. This included code changes that compress the TT entry size and improve the idle loop to reduce resource consumption. The user also made adjustments related to evaluation functions to enhance performance.
ucichess-enginejavascriptstockfish
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