Guillaume Gelin

Entrepreneur, hacker, minimalist, husband, 2x dad. Founding Engineer at Formal (@joinformal).

[Guillaume Gelin @r4mnes]

@jedisct1 Le code est de toute beauté.

[Mokhtar Bacha @AHMB84]

Today, I am excited to share that @joinformal has raised $6.8M in funding led by @ThriveCapital, with participation from @ycombinator , @AbstractVC , and industry leaders such as @jgreze, Alexis Lê-Quôc, @ceo_clickhouse, @stanine, @tidocarriero, @mathile_collin, @Gorintic, @grittygrease, @itsRobPicard and many more.

From writing the first few lines of code in my bedroom two years ago to earning the trust of tech companies I admire—like @NotionHQ, @tryramp, and @GustoHQ journey has been both surreal and humbling.

This isn't just a financial milestone; it’s a recognition of the customers who trust Formal to protect their most sensitive data.

We’re tackling one of the industry’s most complex challenges: securing data everywhere in an organization—from the endpoint to the cloud.

Over the last decade, we’ve seen an explosion of SaaS applications and a surge in the complexity of the data stack, driven by rapid cloud adoption. While this shift has boosted business productivity, it has also made tracking data flows and enforcing granular, context-aware least-privilege policies far more challenging. As a result, organizations face greater exposure to over-privileged access and data oversharing, leading to massive breaches.

Formal is here to change that. Acting like an interface in your favorite programming language, Formal serves as an abstraction layer that brings visibility and control to data flows—all in one place: the network. With Formal, security teams can create policies in a single place and enforce them across their entire data stack and SaaS applications.

If you’re looking to make your data more secure and enable least-privilege on autopilot in your organization, book a demo here: https://t.co/YJxeBw7PtP.

This is just the beginning—our hardest challenges still lie ahead. If you’re excited about our mission and want to join a small, talent-dense team, we’re hiring across GTM and engineering in our SF and Paris offices. Learn more and apply here: https://t.co/eYrkayYr2D.

[Guillaume Gelin @r4mnes]

@ModsMouse @Solvik @bl0tus

[Guillaume Gelin @r4mnes]

@jessfraz I guess it's called "deep tech". :)

[Guillaume Gelin @r4mnes]

@Patrick47159809 @githubstatus @github What a cool ad hominem argument! I'll borrow it next time I see someone posting genuine feedback I disagree with.

[Guillaume Gelin @r4mnes]

@Patrick47159809 @githubstatus @github What is it that you like about the same update repeated every 30 minutes?

[Guillaume Gelin @r4mnes]

@GergelyOrosz I'm French and I can definitely vouch for Zenly engineers. They are indeed one of the strongest teams out there.

[Scaleway @Scaleway]

"Why is it hard to recruit engineers? Because they don't care. About your market cap, your corporate videos or perks. You're the one who needs to care " - @r4mnes, CTO of @refty_co, presents a different recruiting approach #CTOForum @VivaTech

Watch live: https://t.co/3ZmUZYegze

[Guillaume Gelin @r4mnes]

@Natas Si t'avais 119 de QI tu saurais trouver un tel jeu par toi-même ! Les Twittos c'est une cible trop facile pour tes trolls mon Natas. ❤️

[Guillaume Gelin @r4mnes]

@XavMetel @PoliceNationale Pour info, je me suis permis de poster ta vidéo ici, et ça buzz : https://t.co/uj8A3CmELL

[Romaric Philogène 🇫🇷 🇺🇦 @rophilogene]

Our customers are our best contributors. Thank you Guillaume for all the product feedback you made 🙏🙏. It is an absolute pleasure to have you as a customer. Let’s build the future of the cloud together 🚀

Read the complete testimonial of Guillaume here: https://t.co/X5tJDYe8Xu

[Guillaume Gelin @r4mnes]

@joinstationf @refty_co @starton_io @CarbonCroc @ag_rize @Traace_climate @FinenseEU @GoodvestFR @ViewstBuilder @Siffletdata @KsaarSolutions @WhalyHQ 🚀

[Ryan Breslow @ryanbreslow]

At Bolt we've done 10,000+ reference checks.

Crazy right?

Not really. We’ve found them to be the most powerful tool in our talent arsenal.

Here’s the playbook on how to do an A+ reference check 👇👇👇

[Guillaume Gelin @r4mnes]

@BonPote @BonPote gentle ping au cas où tu n'aurais pas vu ma réponse, ma question est vraiment honnête. :)

[Guillaume Gelin @r4mnes]

@BonPote Tu peux expliquer rapidement
(ou me donner un lien qui explique) pourquoi "mettre du nucléaire partout et tout electrifier" ne résout pas le problème ?

[Ultrabug @ultrabug]

I'm scheduled on Wed, Jul 28!

We @Numberly have handed over the stage of our sponsored talk slot to some of the tech associations engaged for social, environmental and educational causes we've been working with for a while: https://t.co/zZn9gL8AGZ

Meet them, Jul 27 #TechForGood

[24h Pujadas @24hPujadas]

📌 #PartiPris #Economique de Stéphane Soumier
📢 : « Fessenheim, stop et sidération »

#24hPujadas #LCI #La26

[Guillaume Gelin @r4mnes]

@Numberly @mkbdfr

[Guillaume Gelin @r4mnes]

@taehatypes yes pls