Julien Sierra
Senior Android Engineer at FREENOW
Albacete, Castile-La Mancha, Spain
Summary
🤩
Rockstar🎓
Top SchoolJulien Sierra is a Senior Android Engineer with a decade of experience specializing in mobile apps and product-first engineering. He combines entrepreneurial autonomy—having founded and led a mobile-focused software shop—with hands-on experience scaling and maintaining large consumer apps at companies like FREENOW, Qonto and New Work. Julien excels at shaping product value through pragmatic, maintainable architectures, while also improving delivery processes across cross-functional teams. Comfortable as a tech lead and a product partner, he has a track record of reducing technical debt, running refactors, and owning releases and client communications. Fluent across English, Spanish and French contexts, he brings a rare blend of startup grit and enterprise discipline to mobile product lifecycles.
10 years of coding experience
7 years of employment as a software developer
Diplôme d'ingénieur TELECOM Nancy Informatique, Diplôme d'ingénieur TELECOM Nancy Informatique at TELECOM NancyAnnée ERASMUS Informatique, Année ERASMUS Informatique at Maynooth UniversityClasse préparatoire Ingénierie, Classe préparatoire Ingénierie at Polytech Nancy
French, English, Spanish, German
Github Skills (25)
ios10
react-native10
cross-platform10
android10
react10
youtube9
mobile9
app-framework8
mobile-development8
todomvc6
ava6
testing6
chai5
traversal5
javascript4
Programming languages (3)
Github contributions (5)
inProgress-team/cordova-camera-canvas
Jul 2015 - Aug 2015
Contributions:31 pushes in 1 month
georgiana-gligor/react-native-youtube
Feb 2017 - Feb 2017
Contributions:1 push in 1 day
react-nativereactyoutube
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