Nicolas Callens
Lead Product Designer at Kestra
Greater Lille Metropolitan Area France
Summary
🤩
Rockstar🎓
Top SchoolNicolas Callens is a Lead Product Designer with 9 years of experience crafting large-scale omnichannel e-commerce experiences and design systems, most recently shaping product at Kestra and previously leading UX/UI for Auchan Retail’s €1.3B online business. He combines hands-on design leadership and team building—having managed and hired multidisciplinary design teams—with rigorous user research and analytics-driven decision making to streamline checkout and cross-device journeys. His background spans agency, gaming, and retail contexts (Ankama, Publicis), giving him a rare mix of creative art direction and pragmatic UX engineering. Nicolas also contributes to backend reliability in open-source tooling—helping fix test race conditions and NPEs in the Kestra workflow automation project—showing a technical curiosity beyond pure interface work. Based in the Greater Lille area, he balances community commitment (co-leading a Montessori school association) with product craft, bringing empathy and operational rigor to design.
10 years of coding experience
CeprecoBac +2, Computer Graphics, Bac +2, Computer Graphics at C.com
French
Github Skills (9)
javas10
orchestrate10
workflow-engine10
orchestration10
orchestra10
java10
testing10
automation9
automations9
Programming languages (6)
Github contributions (5)
kestra-io/kestra
Dec 2024 - Jul 2026
Event Driven Orchestration & Scheduling Platform for Mission Critical Applications
Role in this project:
Back-end Developer
Back-end DeveloperContributions:74 reviews, 172 PRs, 392 pushes in 1 year 7 months
Contributions summary:Nicolas primarily focused on test-related improvements within the Kestra workflow automation platform. Their work involved modifying test configurations, loading specific flows for runner tests, and refactoring test interfaces. They also contributed to fixing issues related to test execution, including race conditions and ensuring the correct loading of test flows. Additionally, they addressed a bug in core functionality by changing the `Objects.equals` call to prevent `NPE`.
event-drivenorchestrationdata-orchestrationhigh-availabilityinfrastructure-as-code
Anorgar/presentation-microservices-micronaut
Apr 2020 - Jul 2020
Contributions:1 release, 17 pushes, 1 branch in 2 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.