Karl Bartel
Partner at cLabs
Berlin, Germany
Summary
🤩
Rockstar🎓
Top SchoolKarl Bartel is a seasoned software leader and engineer with nearly two decades of professional development experience, currently a Partner at cLabs in Berlin. He has held CTO and senior engineering roles, blending full-stack development, data processing with SQL, and pragmatic machine learning to drive product and technical strategy. Karl has substantial blockchain backend expertise from contributing to the Raiden Network—improving token swap logic, balance proof handling, and serializer error handling—and has a track record of shipping robust backend features and documentation updates. Comfortable moving between hands-on implementation and leadership, he brings a history of refactoring complex systems and translating data-driven insights into practical solutions. Trained in computer science at TU Berlin, he combines academic grounding with long-term startup and product-focused experience.
16 years of coding experience
12 years of employment as a software developer
Diplom Computer Science, Diplom Computer Science at Technische Universität Berlin
German, English
Stackoverflow
3,354reputation
410kreached
48answers
8questions
datetime
top-5%
python
top-5%
Github Skills (19)
python10
ethereum10
html10
solidity9
datetime9
blockchain9
backend9
api-design8
testing7
marshmallow7
oracle6
sql6
wiktionary6
math6
significant-digits6
Programming languages (20)
Github contributions (5)
raiden-network/raiden
Nov 2018 - May 2022
Raiden Network
Role in this project:
Back-end Developer
Back-end DeveloperContributions:4 releases, 229 reviews, 572 commits in 3 years 6 months
Contributions summary:Karl's contributions focused on enhancing and refactoring the Raiden Network codebase. They updated documentation to reflect changes in the Geth client version. The commits included restructuring of code and adding more features for token swaps, along with improvements for handling balance proofs, the `Withdraw` message, and the PFS. Additionally, they addressed issues related to fee calculations and improved error handling within the serializer.
paymentsethereumraidenblockchainweb3
pythonjobs/jobs
May 2017 - Apr 2021
A repository for our international job listings
Role in this project:Backend Developer
Backend DeveloperContributions:6 commits, 4 PRs, 4 comments in 3 years 11 months
Contributions summary:Karl primarily contributes to job listing data within this repository. Their work involves creating and modifying HTML files to reflect specific job postings, focusing on the details of the role, company, contact information, and required skills. They have updated existing listings and added new listings for backend developer positions, demonstrating skills in HTML and potentially the project's structure for displaying this content. They are also involved in correcting and updating date formats and text within job postings.
job-listingspythonjoblistingstriggers
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