Julien Guérand

Yosemite Valley, California

A French mind in California

A scientist
who builds worlds
with words & code

Julien Guérand is a French engineer living in Los Angeles — a city that matches his energy: creative, technical, and endlessly sunny. Trained at Pierre and Marie Curie University in Paris, one of Europe's most rigorous science institutions, he brings a physicist's precision to the craft of AI engineering. He'll be the first to tell you he's not Parisian — but from this side of the Atlantic, he'll gladly take the title.

He is fascinated by etymology — tracing the root of words through centuries of meaning. For Julien, language and code share the same DNA: both are systems of rules that, when mastered, let you build anything. He's equally at home around a board game table, approaching every game — from Catan to Go — with the same strategic mind he brings to machine learning.

At Papaya, he turns that mastery into applied AI that makes healthcare less painful for everyone involved.

What drives him

Passions & Pursuits

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Artificial Intelligence

Not the hype — the real thing. Julien builds AI systems that solve genuine problems: in healthcare, in language, in the messy middle of human complexity. He believes intelligence, artificial or otherwise, is only useful when it's applied.

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Etymology

Words are archaeology. Every word carries centuries of meaning inside it.

Algorithm ← al-Khwārizmī, 9th-c. Persian mathematician

Robot ← Czech "robota" (forced labor, 1920)

Julien ← Latin "Iulianus" ← Julius Caesar

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Board Games

From strategy heavyweights to quick-fire party games — Julien plays them all with the same analytical intensity he brings to AI.

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🧀

Fromage

Comté, Reblochon, Époisses, Beaufort. Do not argue with him about this.

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California Outdoors

Yosemite, the Sierras, the Pacific coast — Julien embraces California's scale fully. France has Alps. California has the light.

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French Culture

Not technically Parisian — and he'll correct you on that. But from Los Angeles, it's close enough, and he's learned to smile and accept the compliment.

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Table Tennis

Not just a player — an incredible one. Julien brings the same precision and reflexes he applies to AI to the ping-pong table. Fast, focused, and very hard to beat.

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Where he works

Role at Papaya

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Senior Applied AI Engineer

Papaya Payments · Los Angeles, CA

Julien builds and deploys applied AI systems at the core of Papaya's healthcare payment platform. His work spans machine learning, natural language processing, and intelligent automation — helping healthcare providers and patients navigate financial complexity with less friction and more clarity. He's the engineer who turns AI from buzzword into working product, with a scientist's discipline and a builder's instinct.

Where he was formed

Education

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Pierre and Marie Curie University (UPMC) · Paris, France

One of Europe's top science and engineering universities — ranked among the world's best for mathematics, physics, and computer science. Named for two Nobel laureates. It is where France's finest scientific minds are shaped, and where Julien's rigorous approach to everything was forged.

His world

Family

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Julien, Ann & Chloé

Julien is the proud father of Chloé and husband to Ann — his greatest adventure, together. Ann is the horse lover of the family, bringing that passion for strength, grace, and open fields to their Los Angeles life. Raising a daughter while staying rooted in French language and culture keeps things rich, full, and wonderfully complicated.