Johannes Castner
Chief Executive Officer at CollectiWise Technologies
San Francisco, California, United Kingdom
Summary
👤
Senior🎓
Top SchoolJohannes Castner is a technology and strategy leader with 11 years blending AI research, product-led startups, and academic teaching to build systems that amplify collective intelligence. As CEO of CollectiWise and former Director of Intelligent Systems at Towards People, he designs agentic, privacy-first analytics and deliberation platforms (including NICER) that fuse semantic AI with structured human judgment for evidence-based decisions. His background spans semantic NLP and recommendation work at eBay, Google Cloud data engineering, and applied econometrics research, giving him rare fluency across ML, data warehousing, and causal inference. He also co-founded a heterophily-driven social platform, teaches AI ethics and behavioral science, and holds degrees from Columbia with time at Harvard—reflecting an orientation toward societally minded technical innovation. An underappreciated thread in his career is a persistent focus on governance-by-design: building systems that make values and accountability primary constraints, not afterthoughts.
11 years of coding experience
7 years of employment as a software developer
Exchange Scholar Political Economy, Exchange Scholar Political Economy at Harvard UniversityMaster of Science - MS Sustainable Development, Master of Science - MS Sustainable Development at Columbia University
English, German
Stackoverflow
69reputation
9kreached
1answer
10questions
Github Skills (44)
azure6
owl6
bioinformatics6
conceptnet6
google-cloud-sql6
raw-data6
dns6
google-colaboratory6
bots6
google-cloud-dataflow6
python6
semantics6
gcp6
django6
facebook6
Programming languages (8)
Github contributions (5)
jac2130/bayesLearn
Feb 2016 - Nov 2018
Contributions:57 commits, 4 PRs, 45 pushes in 2 years 9 months
CollectiWise/collectiwise
Dec 2018 - Apr 2020
Code that allows collectives to reason together through market and demcratic institutions
Contributions:1 PR, 53 pushes, 1 branch in 1 year 3 months
pythonmarketinstitutions
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