Hakan Kjellerstrand
Software Developer (retired) Independent Researcher at http://hakank.org/
Malmo, Skåne County, Sweden
Summary
👤
Senior🎓
Top SchoolHakan Kjellerstrand is a retired software developer and independent researcher with 12+ years of professional experience building web-based systems and e-commerce platforms, notably contributing to bokus.com. His academic background spans computer science, theoretical philosophy and political science, which informs a methodical approach to constraint and logic programming, probabilistic modeling, and statistical analysis. A long-time practitioner of languages such as Java, Perl, PHP, Ruby and R, he is also a co-author of the Picat book and an active blogger on constraint programming and AI topics. Known as a "senior bollplank," he combined hands-on development with mentoring and pre-sales technical advising across project lifecycles. Even in retirement he continues to publish research, tutorials and recreational mathematics, blending formal modelling with practical software craftsmanship from his base in Malmö.
13 years of coding experience
22 years of employment as a software developer
Computer Science, Computer Science at Lund UniversityTheoretical Philosophy, Theoretical Philosophy at Lunds universitet
Stackoverflow
6,759reputation
171kreached
197answers
3questions
Github Skills (59)
answer-set-programming10
combinatorics10
python10
ampl10
jgap10
eclipse-clp10
comet10
picat10
constraint-satisfaction10
essence10
z3py10
minizinc10
sicstus-prolog10
gecode10
constraint-programming10
Programming languages (12)
Github contributions (5)
nfzhou/fzn_picat
Nov 2020 - Aug 2025
Contributions:3 PRs, 2 comments in 4 years 10 months
hakank/hakank
Aug 2013 - Jan 2023
My public programs and models - mostly combinatorial problems and puzzles
Contributions:529 commits, 6 PRs, 260 pushes in 9 years 6 months
cometpythonproblemscombinatorialconstraint-programming
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