How I built an app without being a developer: Kumul’s story

Where did I come from before Kumul?

Not from a business school, and not from a computer engineering school. My path is more a series of very different grounds, and I think that is what led me here.

Years	What I was doing	Where
2012 - 2018	Bac STI2D (French technology high school diploma), then BTS CRCI (a two-year technical diploma), lycée Jean Perrin	Marseille
2014 - 2019	Student jobs: delivery driver, cashier	Marseille
2015 - 2017	Handball coach at the SMUC club	Marseille
2018 - 2019	Maintenance training (third year) at IRUP, as a work-study apprentice in the nuclear industry at ADF	Saint-Étienne
2018 - 2024	Boat rental, independent	Marseille
Since 2019	Property dealer, independent	Béziers
2019 - 2022	Nuclear industry, Engie	International
2022 - 2024	DJ, independent	Marseille
2022 - 2026	Nuclear industry, Framatome	France
Since 2026	Founder and CEO of Kumul	Paris

The full story is also on my history page (in French), and the key facts about Kumul are on the About Kumul page, in English.

What did the nuclear industry teach me about building a company?

Far more than you would think. In nuclear, nothing is left to chance, and that is exactly what I apply to Kumul:

• Rigor and reliability: a plant has to work every single time. So does an app, otherwise nobody comes back.
• Redundancy: there is always a plan B. When something breaks, you already need to know how to keep going.
• Teamwork and communication: on a site, everyone relies on everyone else, and a badly passed message is expensive.
• Adapting: from one site to another, from one country to another, nothing ever goes exactly as planned.
• Thinking like a business owner: taking responsibility, meeting deadlines, being accountable.
• Work, simply. A lot of it, every day.

What I can say without hesitation: working every day, in France and abroad, I saw the same reality. People with passions, projects, sometimes very precise dreams. And very few of them getting started.

What made me want to create Kumul?

I saw it around me, and in myself too, sometimes. You don’t give up on your life all at once. You postpone it, one evening of scrolling after another. You spend hours watching other people’s accounts, while the sport you loved stops and the project you wanted to launch sits in a corner.

The trigger was seeing this problem around me, then realizing it was not specific to my circle. It was everywhere: among students, employees, friends, in France and abroad. When a problem shows up wherever you look, you stop assuming someone else will fix it.

I don’t believe people lack people around them. What they lack are simple occasions to meet up and do what they love. You want to run a marathon? You need three people to train with on Tuesday evenings. You want to study seriously? You need a table and two people from your class. That is what I wanted to make easy.

Did my years as a coach and an independent count?

Yes, and that may be where Kumul really began.

As a handball coach, I learned three things I use every day:

• A group motivates. Alone, you give up quickly. In a group, you show up because others are counting on you.
• Getting people to come, then to stay. The hardest part is not the first practice, it is making people want to come back to the next one.
• Sport creates bonds. Friendships are born on the pitch far more easily than around a screen.

As an independent (boat rental, DJ, property dealer), I learned the rest:

• Starting without a safety net: nobody brings you your customers, you have to go and find them.
• Bringing people together: a boat trip or a party is about creating a moment where people meet. Kumul is the same idea, for everyone.
• Running a project from A to Z: numbers, negotiation, organization, and owning it when it doesn’t work.

How did I build Kumul without being a developer?

I did not have a developer background. I learned.

Today, the Kumul app, the website and the mobile version heading to the stores were built by me, with AI as a copilot. Not an agency. I struggled, and some days I still do. But it gives me an advantage: when someone tests Kumul and tells me "that is useless", I can fix it fast.

What I did, in order, so as not to build in a vacuum:

1. Interviews and tests with future users: without the app, with the app, then with a teacher.
2. Four workshops with a consultant, who helped me narrow the project down and speak more simply.
3. Successive names: the app was called NEW LIFE!, then NV, then UNIT, before becoming Kumul. Better to change early than late.
4. One question before every feature: does this help someone go out and do an activity, yes or no? If not, it doesn’t go in.

The best example: likes and scores. Every app has them, and they are what keeps people on their screens. I refused them. On Kumul, we don’t count who is popular, we look at what people actually do together.

Why did I choose Paris?

I had been advised to launch in Marseille, close to home, where I could be present every day. It was good advice. I decided otherwise: my life and my energy were already shifting to Paris, and a founder who is only half there is worth nothing. So Kumul was born in Paris in 2026, and it is starting in French schools and universities.

What does Kumul actually do?

You open the app and see the activities around you. A climbing session tomorrow, a study session, a five-a-side football game looking for two players. You join in one tap. And if what you are looking for doesn’t exist, you propose it, and others join you.

• Three categories: Sport, Studies / Career projects, and Culture.
• No likes, no scores: we count what you do outside the app, not the time you spend in it.
• "Confiances" (trusted connections) rather than followers: the people you actually do things with.
• Free for students.
• In French, in France: currently a web app at app.kumul-app.com, with the mobile app coming to the App Store and Google Play.

If you are wondering why so many people look for company this way, I have gathered the figures in student loneliness in France, and compared the options in apps to meet people in France.

Where am I today?

At the beginning. I am building Kumul in the open, brick by brick, with the progress and the walls I run into. My dream, deep down, is a big one: that time spent on a screen finally helps people live their passions and reach their goals. But what keeps me busy every day is much simpler: that someone finds, this week, a person to do the thing they have been putting off for months.

If this story speaks to you and you live in France, create your account and see what is happening around you. And if you are building something too, write to me!