Jonas Lellky
Senior Software Engineer (Consultant) at Highcap AB
Greater Stockholm Metropolitan Area Sweden
Summary
🤩
Rockstar🎓
Top SchoolJonas Lellky is a Senior Software Engineer and consultant with 11+ years building scalable web applications, e-commerce platforms, and internal tools for clients like Spotify, Blocket and the Swedish Research Council. He blends frontend expertise (React, TypeScript, UX/SEO) with backend systems (Node.js, Scala, Kubernetes) and a practical focus on testing and CI/CD from his own consulting firm. Jonas contributes to prominent open-source Home Assistant work, adding BACnet/Flexit climate control integrations and robust testing for local-first IoT automation. Comfortable running cross-functional workshops and designing data models for research-grade systems, he pairs technical craft with clear written communication for distributed teams. Outside code he brings a hands-on, product-minded curiosity—automating his home, designing storage for camper vans, and documenting adventures through photography and travel writing.
10 years of coding experience
9 years of employment as a software developer
KTH Royal Institute of TechnologyTumba gymnasium
English, Swedish
Stackoverflow
21reputation
75reached
0answers
1question
Github Skills (12)
bacnet10
asyncio10
iot10
home-assistant10
sensor10
python10
home-automation10
sensor-fusion10
testing10
unit-testing9
html6
css6
Programming languages (9)
Github contributions (5)
home-assistant/core
Jan 2020 - Feb 2025
:house_with_garden: Open source home automation that puts local control and privacy first.
Role in this project:
Back-end Developer / IoT Developer
Back-end Developer / IoT DeveloperContributions:61 reviews, 33 PRs, 108 comments in 5 years 2 months
Contributions summary:Jonas primarily contributed to the integration of the Flexit Nordic (BACnet) system within the home assistant core. Their work focused on implementing climate control functionality by adding support for sensors, binary sensors, switches, and number entities for controlling fan setpoints. They also contributed to the configuration flow, error handling, and testing of the Flexit integration, including refactoring and the addition of tests to improve the quality and reliability of the code.
raspberry-pipythonhouseprivacy-firstasyncio
lellky/howto-magic-mirror
Oct 2020 - Mar 2025
Building a magic mirror with home assistant as backend
Contributions:4 PRs, 6 pushes, 3 branches in 4 years 5 months
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