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Sébastien Balieu
Freelance web developer in Brussels

You're talking to the person who writes the code.

I'm Sébastien. I design and build websites, business applications and automations for innovative companies. No project manager between us, no subcontracting.

  • Freelance developer in Brussels
  • Reply within 24 h
  • Fixed-price quote
15 years of development experience First line of code at age 8
30+ projects delivered Websites, business apps, automations
3 companies founded One More Pixel, Coddy, Numinam
9 countries Coddy's European rollout
1 point of contact From the first call to launch

What I sell today, I first built for myself.

Four steps, and what each one taught me.
01

2016

I set up my own company.

A Frenchman living in Brussels, I started One More Pixel and began building for Belgian clients. Websites, applications, integrations. One lesson stood out: most projects fail on scoping, not on the technology.

02

2018

I moved to the other side of the table.

I co-founded Coddy, urban escape games for consumers and companies. We raised funds and rolled out across nine European countries. That's where I learned what carrying the risk feels like: slipping deadlines cost real money, and it was mine.

03

2020 to 2024

I automated everything.

Running Coddy in nine countries without growing the team meant automating the rest. Quotes, booking, payment, game preparation, delivery to players. Today we only step in manually for about ten per cent of customers. That wasn't a technical showcase, it's what made the business viable.

04

2025

I launched Numinam.

Back to freelance development, with what I learned as a founder. I now know what a business owner looks at in a quote, and why they hesitate to sign it.

What I do

Three crafts, one person doing all three. Nobody passes the ball between the design, the code and the launch.

Design.

Design.

Turning a business into user journeys, a site structure and screens. Asking the right questions before drawing, and drawing before coding. It's the part most projects skip, and the most expensive one to fix afterwards.

Build.

Build.

Fast websites and complete business applications, from the data model to the interface. I take the project end to end: design, development, launch, handover to your team.

Automate.

Automate.

Connecting your tools to each other and making the tasks that come back every day disappear. Request handling, data entry, follow-ups, reporting.

Laravel, Vue, Astro, Ionic, n8n, MySQL, API integrations.

How I work

Three phases. At each one, you know where the project stands and what it costs you.
1 Understand

Understand.

We start with a free twenty-five-minute call. If the project makes sense, we move to a paid scoping phase: I look at your business, your tools and your goals, and hand you a written scope with a fixed price. You can walk away with that document and have it built elsewhere. It has happened.

2 Build

Build.

You sign off at every step: structure, copy, design, then development. You watch the project progress on a staging link, not in a weekly report. I never invoice an overrun I haven't flagged before producing it.

3 Continue

Continue.

After launch, your team is trained and the code is yours. You can keep me on for what comes next or take it from here. Either works for me.

The limits

A company is defined by what it doesn't do.

For me, that means:

Subcontracting.

The code you receive is written by the person you're talking to. If a project needs extra hands, I tell you, and you know who is involved.

Starting without a scoping document.

A project launched on a verbal brief ends in a disagreement about scope. Scoping protects both sides, yours as much as mine.

WordPress and the other granddad CMSs.

Plugins to maintain, updates that break the layout, and pages that take several seconds to open. I build with Astro: nothing to update every month, a load time under one second, and code that belongs to you.

Selling you things you don't need.

A brochure site doesn't need an application framework. A business application doesn't need AI to work. I'll tell you when you don't need what you came for.

What the owners who signed say

Belgian and European SMEs, on projects that are live today.

Sébastien is always attentive and understood our needs perfectly when it came to redesigning our website! The new site looks great and was delivered on time. We've already gained a few customers thanks to the improved SEO of the new site
Didier Boulvin

Didier Boulvin

Coddy

Numinam's contribution to the development of our App has been significant in its success with our B2C and B2B customers.
Stephane Draux

Stephane Draux

Founder • Spengo

Numinam (One More Pixel) is doing a fantastic job for Euronet. They’ve started the mission in saving our web-site from a cyber-attack. We had lost a lot of information and they had to rebuild our web-site. They had to recover the data left on our…
Valérie Van Belle.

Valérie Van Belle.

Managing director • Euronet

At Nallian we build solutions that are trusted by the world's leading airports, ground handlers and logistics companies. But our website no longer reflected that level of excellence. This redesign ensures our first impression matches the quality of…
Jean Verheyen

Jean Verheyen

CEO • Nallian

The new website much better reflects who we are. It tells our story more clearly, it's easy to navigate, it looks fresh and modern. It is more Nallian.
Joke Aerts

Joke Aerts

Director of Marketing • Nallian

Numinam's technical and design vision has enabled us to improve our lead generation flows. A big step forward.
Jérôme Van De Sande

Jérôme Van De Sande

Product & Data Leader • Heat Me

Numinam has completely modernized our website. The design is clearer, more credible, and our visitors understand what we do. A real leap in quality. Also worth noting is the excellent collaboration between Numinam and our development agency. Thank…
Olivier Lafosse

Olivier Lafosse

Founder & CEO • Heat Me

It was a real pleasure to do business with Sebastien. He did a great job and transform our inefficient and boring website to a nice one that generate leads. Moreover, Sebastien is a patient and reliable partner and he's always ready to help.
Shirley Boterdael

Shirley Boterdael

Marketing & Com. Manager • Highcodata

Freelancer, agency or online platform?

All three have their use. The table also says when I'm not the right choice.

Budget for a brochure site

Freelance developer
€3,500 to €7,000
Web agency
€8,000 to €25,000
Online platform
€500 to €2,000

Who you talk to

Freelance developer
The person who codes, from first call to launch
Web agency
A salesperson, then a project manager, then a developer
Online platform
A chat widget and a help centre

Time to a decision

Freelance developer
Reply within 24 h, decision on the call
Web agency
Committee, then a quote in 1 to 3 weeks
Online platform
Immediate

Custom work

Freelance developer
Design and code written for your business
Web agency
Custom, depending on budget
Online platform
A template to fill in

High volume, several crafts in parallel

Freelance developer
My limit: two projects at a time
Web agency
This is where the agency wins
Online platform
Not applicable

Ownership of code and accounts

Freelance developer
Yours from day one
Web agency
Depends on the contract
Online platform
You rent, you don't own

The questions people don't dare ask a freelancer

Including the ones whose answer isn't flattering.

What happens if you fall ill in the middle of the project?

The schedule slips by the length of my absence, and I tell you the same day. On critical projects I work with two independent developers who know my code and can take over. I tell you during scoping whether your project falls into that category.

How many clients do you handle at the same time?

Two development projects in parallel, maximum. That is why there is sometimes a wait before I can start, and it is also why you get an answer within twenty-four hours when you write to me.

What is your current lead time?

The next possible start is the week of 14 September. Until then, the twenty-five-minute call and the scoping phase can still happen: that is exactly the moment to do them, so development starts on a scope that is already written.

Who takes over the code if we stop working together?

You own the repository and the hosting from day one. The code uses mainstream technologies and it is documented. Any developer can pick it up, and I run the handover if you ask for it.

Why a freelancer rather than a web agency in Brussels?

For three measurable reasons: you talk to the person who codes, the decision happens on the call instead of in a committee, and the budget for a brochure site sits around €3,500 to €7,000 instead of €8,000 to €25,000.

The agency is still the right call in three cases: a high volume to produce in parallel, a need for several crafts at once (media campaign, video production, development), or an internal requirement to contract with a company of a certain size. If you are in one of those cases, I will say so during the call.

Do you work with companies outside Brussels?

Yes, anywhere in Belgium and remotely elsewhere. The first meeting is on video in every case.

Do you bill by the day or by the project?

By the project, at a fixed price set after scoping: you know the amount before the first line of code is written. Day rates (€700 per day) remain possible for long engagements at a client who already has a team.

What happens if the project goes beyond the agreed scope?

I flag the overrun before producing it, with what it costs and what it delays. You decide. I don't invoice an overrun you discover on the invoice.

The simplest thing is to talk.

The simplest thing is to talk.

Twenty-five minutes, on video, with no preparation on your side. You tell me what you want to build, I tell you whether it's feasible, at what price and in what timeframe.

If it isn't for me, I'll point you elsewhere.

Book my 25-minute call