// freelance lead software engineer
Antoine Coulon
Lead Software Engineer · Freelance · Paris
I help teams ship resilient, scalable, evolvable software through full-stack engineering, craftsmanship and lean delivery. I also build open-source developer tools.
// open source
Open source & devtools
All-in-one devtool to analyze, search and visualize the dependency graph of your JavaScript / TypeScript / Node.js projects.
View on GitHub →A practical introduction to Effect and the rationale for adopting it in a TypeScript codebase.
View on GitHub →Zero-dependency library to build and traverse Directed Acyclic Graphs in JavaScript.
View on GitHub →Run NodeSecure's SAST/SCA security analysis automatically in your CI pipeline.
View on GitHub →// writing
From the blog
Errors as values: typed errors vs defects
Not every error belongs in your types. How to separate recoverable domain [...]
June 11, 2026 AIFaster with AI without burning out: Agentic Coding done right
Why AI exhausts so many dev teams, and how Agentic Coding done right lets you [...]
June 9, 2026 ConcurrencyFunction coloring: when sync and async become an implementation detail
The Function Coloring problem between sync and async functions, and how Effect [...]
March 17, 2026 ArchitecturePush notifications: a distributed system in its own right
From template to device: how mobile push notifications actually work, their [...]
January 15, 2026 AIAI is revolutionizing how we write software, not the engineer's role
AI is transforming how we write software, but not the engineer's mission [...]
January 12, 2026 AIThe underestimated advantage of AI
An AI agent aligns easily with a team's standards, but it amplifies the good [...]
December 22, 2025// speaking
Talks & podcasts
Structured Concurrency: the hidden power behind Effect
Effect Days Conference #2Uncovering Fibers: the hidden power behind the Effect library
Effect Paris meetup #3
Building skott: a journey of Effect-Driven Development
Effect Days Conference #1
Effect introduction, the whys
Paris TypeScript meetup #35
Effect introduction for TypeScript
Hands-On podcastUnleashing the power of graphs with skott
Accelerator meetup #1// recommendations
What people I've worked with say
Antoine consistently demonstrated outstanding technical expertise and a proactive mindset, taking the initiative to propose impactful topics and drive them to completion with remarkable ownership. I strongly recommend him.
He puts engineering at the service of the product, with an iterative, impact-driven approach. He takes ownership of key deliverables and drives them autonomously, while keeping communication excellent with the team and stakeholders.
Antoine always delivered high-quality functionality, focusing on how his features would actually be used. His professionalism, technical expertise and commitment to quality are exceptional.
A true professional who readily takes ownership of his projects. Curious and attentive, his critical thinking always brings relevant, constructive insight, and he's always there to share his knowledge.
An outstanding software engineer with a keen eye for detail. Not only highly skilled but also a great mentor who genuinely supports his teammates. Any team would be lucky to have him.
By far one of the best engineers I have ever worked with. Very highly skilled and very patient and willing to share his knowledge. He was pretty much my go-to whenever I got stuck on anything.