Johannes Kettmann
Chief Executive Officer at Office Walker
Berlin, Germany
Summary
👤
Senior🎓
Top SchoolJohannes Kettmann is a pragmatic software leader and founder with 10 years of experience building scalable React frontends and Node.js backends, currently serving as CEO of Office Walker and Senior Software Developer at Contentful. He blends hands-on engineering—having led architecture and checkout systems for high-traffic banking apps—with an entrepreneurial mindset demonstrated by founding Profy.dev, a React training platform driving ~10k monthly organic visits and ~100 students. Comfortable across product, design and ops, he introduced CI/CD with GitHub Actions and has repeatedly delivered cross-team libraries, testing improvements, and white-label solutions. Based in Berlin and trained in physics, he favors clean code and practical architectures that align tightly with user needs and business goals. An interesting detail: he pairs product-building (physical hardware at Office Walker) with dev-centric education, bridging hardware, web platforms and community-driven learning.
10 years of coding experience
8 years of employment as a software developer
Diplom Physik, Diplom Physik at University of Potsdam
Github Skills (200)
simulator10
low-code10
relay-modern10
marker10
integrations10
automation10
visual-studio10
google-map10
relay10
data-driven10
javascript10
modularity10
no-code10
editor10
enums10
Programming languages (10)
Github contributions (5)
ooloo-io/reddit-timer-rotegras
Mar 2020 - May 2020
Contributions:1 branch, 118 comments in 2 months
jkettmann/react-architecture
Dec 2023 - Jul 2024
Contributions:13 PRs, 63 pushes, 13 branches in 6 months
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