About

20 years of experience
in product, ecommerce, UX/UI and development.

I'm Sébastien Balieu. I headed digital marketing at Walibi and then at Zetes, founded a web agency in Brussels, co-founded Coddy and now publish Harmonia. I carry out every audit myself and stay your contact from start to finish.

Since 2006
20 years
Of digital marketing: in-house, agency-side, then running my own products.
Coddy
9 countries
More than 250,000 players served by the urban games platform I co-founded.
Coddy
+31%
Conversion rate since the site redesign went live on 1 September 2026.
Harmonia
+156%
Revenue in one month for the family app I publish.

My career

Twenty years of selling online, in-house, agency-side and as a publisher.

2006
AvantageGolf
Digital marketing manager
One of the first online golf shops in France, launched between London and Paris when nobody believed in it.
2009
Walibi
Digital marketing manager
The digital transformation of the parks in Belgium, France and the Netherlands, and online ticket sales for several of them.
2014
Zetes
Digital marketing manager
Acquisition and marketing automation for large B2B accounts, then the redesign of a site with more than 1,000 pages, in 8 languages, for 17 countries.
2016
One More Pixel
Founder
A web agency in Brussels building websites and business apps, and the lesson that a poorly scoped project gets complicated long before the technical work does.
2018
Kalio
Co-founder
One More Pixel becomes Kalio, a web and mobile agency co-founded with Didier Boulvin and Stéphane Draux, and gets its first team of developers.
2020
Coddy
Co-founder and CEO
An urban escape games platform, funded in 2022 and used by more than 250,000 players in 9 countries.
2025
Harmonia
Publisher
A mobile app that helps families track children's chores and rewards, released in November 2025 on the App Store and Google Play.
2025
Numinam
Founder
Conversion rate optimisation for websites, online shops and apps: every change shipped, then measured.