Kai Sellgren
Software Consultant & Founder at Upsoft
Helsinki, Finland
Summary
👤
SeniorKai Sellgren is a seasoned software consultant and founder based in Helsinki with 14 years of experience building complex web systems and developer tooling. He founded Upsoft and earlier Cindela, where he focused on full-stack solutions using Dart, PostgreSQL and MongoDB and became a top Dart contributor on StackOverflow with 125+ answers. His background spans product-focused engineering at Reaktor and large-enterprise tooling for Outotec, delivering solutions that sped up sales processes and operational workflows. Kai also authored several open-source Dart libraries (Zip, SMTP client, CRC32, animation/inbetweening) and contributed to the Dart MongoDB drivers, showing a mix of practical engineering and platform-level contributions. He combines entrepreneurial drive with hands-on implementation skills, comfortable taking projects from architecture to production. An often-overlooked strength is his sustained commitment to developer ergonomics, demonstrated by both open-source tooling and high-impact internal tools.
14 years of coding experience
6 years of employment as a software developer
English, Finnish
Stackoverflow
29,164reputation
1.4mreached
143answers
34questions
inheritance
top-5%
javafx
top-5%
enums
top-5%
sorting
top-5%
fxml
top-5%
redirect
top-5%
Github Skills (200)
testing10
automation10
nike10
epoch10
javascript10
chromium10
email-validation10
compose10
firefox10
api10
pdfium10
dart10
developer-tools10
js-api10
node-module10
Programming languages (8)
Github contributions (5)
kaisellgren/CRC32
Aug 2012 - Sep 2014
A cyclic redundancy check calculator written in pure Dart.
Contributions:15 commits in 2 years 1 month
dart2dartcycliccalculatorcyclic-redundancy-check
kaisellgren/ScalaGit
Sep 2013 - Apr 2014
Contributions:60 commits in 6 months
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.