Julien Truffaut
Software Engineer at Scala Jobs
Vienna, Austria
Summary
🤩
Rockstar🎓
Top SchoolJulien Truffaut is a seasoned backend engineer with 13 years of experience building resilient systems for startups and tech giants, currently working at SiriusXM from Vienna. He’s a prominent figure in the Scala and functional programming communities: author of the widely used Monocle optics library and contributor to flagship projects like circe, cats, frameless and http4s. For the past five years he has run practical FP training (fp-tower), translating advanced concepts into simple techniques that drive measurable business value. Julien also co-founded niche job platforms for Scala and Rust, demonstrating a commitment to developer communities and diversity. His background blends rigorous academic training (Oxford, Télécom Paris) with hands-on production impact, from Amazon retail pipelines to productionising ad systems at zeebox.
13 years of coding experience
13 years of employment as a software developer
MSc Computer Science, MSc Computer Science at University of OxfordDiplôme d'ingénieur Computer Science, Diplôme d'ingénieur Computer Science at Télécom ParisLicence Mathématiques et Informatique, Licence Mathématiques et Informatique at Université Paris Cité
French, English
Stackoverflow
497reputation
10kreached
11answers
2questions
Github Skills (26)
unit-testing10
json10
spark10
url-encoding10
typeclass10
urn10
http10
prism10
data-structure10
scala10
scalatest10
lenses10
uri10
data-structures10
cat10
Programming languages (9)
Github contributions (5)
optics-dev/Monocle
Jan 2014 - Oct 2021
Optics library for Scala
Role in this project:
Back-end Developer
Back-end DeveloperContributions:4 releases, 84 reviews, 1241 commits in 7 years 10 months
Contributions summary:Julien implemented core functionality in a Scala library for optics. They primarily refactored existing code to enhance the library and added new features such as the ability to compose different optics (Lens, Prism, etc.) and methods for more convenient code handling. Their work centered on introducing new data structures and improving the structure of existing classes to increase the flexibility and ease of use of the Monocle library.
scalafunctional-programmingopticslenstypelevel
typelevel/cats
Jan 2015 - Aug 2018
Lightweight, modular, and extensible library for functional programming.
Role in this project:Back-end Developer
Back-end DeveloperContributions:62 commits, 45 PRs, 36 pushes in 3 years 7 months
Contributions summary:Julien primarily contributed to the `cats` library, focusing on adding and modifying data structures and typeclasses related to functional programming. Their work included implementing the `Show` typeclass, the `Const` data structure, and the `Or` and `OneAnd` types with associated instances. They also implemented typeclass methods, corrected typos, and updated implicit usages, demonstrating a solid understanding of the library's internal structure and core concepts.
functional-programming
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