Build your quality web application today

By creating your application with a trusted web development agency, you control the design and functionalities, strengthening your online presence and engagement with your audience.

prototypage et tests utilisateurs sur le terrain
applications web
applications web educ'arte


In the digital age, where web applications are radically transforming the business landscape, 40/60 Studio, a web agency specializing in innovation, is positioned as a key player in the creation and development of custom web applications. Based in Paris and also present in Nantes, our agency excels in the development of business web applications and SaaS solutions, thus offering our customers powerful tools to optimize their performance and productivity.

The tailor-made expertise of 40/60 in web applications

We bring together a wide variety of experts, whether in terms of design or web development. Thus, the studio excels in the production and design of tailor-made web applications and mobile applications, turnkey and meeting the specific needs of each project.

We are among the best agencies in Paris, in particular due to our experience and our ability to adapt to all types of projects.

interface web applications ADN Data

Technical skills at the service of your web application

Our broad expertise ensures results and a personalized user experience. Our design and development methods adapt to all environments, even the most demanding ones.

workshop d'équipe centré utilisateur

A personalized, user-centered approach

Each web application we create is the result of close collaboration between target users, you, our designers and web developers, ensuring a perfect symbiosis between functionality and usability.

accompagnement en equipe

The assurance and reliability of our support

Our expertise is not limited to the visual aesthetics of web applications, it is dedicated to being a tailor-made partner for each challenge.

Our offers in web applications for Start-ups and big companies

visuel représentatif offre startups

Our offers for start-ups

We understood very well that the launch of a web application is a key moment for a young start-up, which often leads to growth. Our services for start-ups include:

Ergonomic definition

We work closely with you to define the ideal ergonomics of your product, ensuring that it perfectly meets user expectations.

Launch offers

Our launch solutions are designed to ensure that your product makes a memorable first impression, with an intuitive and engaging customer user interface.

Boost to reach your product market fit

We help refine the ergonomics of your product so that it resonates perfectly with your target market, thus increasing your chances of achieving product market fit.

Understanding uses

We start with a thorough analysis of user behaviors and needs to ensure that our solutions are fully aligned.

Identifying opportunities

By identifying opportunities for improvement, we implement ergonomic strategies that maximize efficiency and commitment.

Realization of POC (Proof of Concept)

We develop prototypes to test and validate our ergonomic concepts, thus ensuring their effectiveness before full deployment.

Digital redesign

We offer redesign services to modernize and improve the ergonomics of your existing products, aligning them with the latest trends and technology.

visuel représentatif offre grandes entreprises

Our offer for large companies

In order to guarantee a personalized “Taylor-made” approach, we do not adopt a fixed process for large groups. Our aim is to ensure that all expectations are taken into account.

Innovative technologies for your project web application.

We use modern and efficient tools to stay up to date. These tools embody efficiency, creativity, and harmonious collaboration

logo Vue JS

JS view

Vue.js, a JavaScript framework, simplifies the development of responsive web applications. Flexibility, easy integration and reusable components make it the preferred choice of our agency for modern and efficient applications.

logo React JS

React JS

React.js, a JS library by Facebook, simplifies the creation of interactive interfaces. Appreciated for its modularity, it facilitates web development with reusable components.

logo webflow


We use Webflow to translate creative concepts into interactive, aesthetic and quality websites that meet the specific needs and specific businesses of our customers.

A macro overview of our software

These powerful tools are just a glimpse of the software integrated into our daily workflow, thus ensuring tailor-made innovations for solutions adapted to the unique needs of our customers.

New development methods day after day

At the forefront of innovation, we are experimenting with new methods of design and development. Webflow is at the heart of this transformation, explore new methods of creation and development for your web application or mobile application with our agency using the DevLink method.

Our web application development methodologies used among the best agencies make it possible today in particular to accelerate the launch and the referencing of your project.

The approach proposed by our web application agency

At 40/60, our methodological approach ensures the perfect balance between business goals and the needs of end users. Here's how:



User research and clarification of needs

Objective: Gather user needs and/or business constraints in order to consider solutions in line with their expectations.

Method: We conduct interviews in the field to gather the needs of the target people. Our experts then analyze the results to draw lessons from them presented in a report, thus guiding further discussions.

livrables recherche utilisateur web application


Definition of uses and selection of needs

Objective: Refine thinking while maintaining a user-centered vision.

Method: Our web agency outlines the needs of your application or even before thinking about its design. Thus, we think with logical paths to better clarify the actions.

workshop définition application web


Interface design

Objective: Land at clear, thoughtful and documented models.

Method: Our agency works in two stages for the design of interfaces, we start with a wireframe logic (low fidelity model, without graphic style) in order to test and validate the entirety of your web application. Then, our design experts create UI models (high fidelity) that include all the graphical part of the interfaces.

conception interface web application

User tests

Prototyping and user testing

Objective: Collect concrete data on user interactions on the web application.

Method: The teams proceed with the development of a real prototype in order to put the product into a real situation. Thus, we can collect concrete data that can then be used to make adjustments to the models in order to best correspond to business expectations/constraints.

prototypage et tests utilisateurs sur le terrain


Development & integration

Objective: Make your web application real and technically usable.

Method: Our web design and development experts work in collaboration in order to achieve as much as possible what was decided during the user interface design phases. Our developers create all the models and set up a modern technical architecture in order to meet the requirements of the best web applications as much as possible.

développement et intégration web application

A project in mind?
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The creation of web applications,
A challenge taken up with them.

Explore our rich portfolio of web applications for
assess the quality of our agency.

DNA Data

Helping data DNA convert and retain its users

2 projects — Now operating on the market

Customer case: Redesign of the ADN Data platform and the website
visuel cas client ADN Data

Educt' Arte

Redesign Arte's education platform, for schools.

2 products — To redesign different paths of the platform

Customer case: “Educt'Arte” platform
Mockup de la plateforme pédagogique Educ'Arte

Discover all of our achievements

To conclude

In short, 40/60 Studio is more than just an innovation and creation agency - it is a partner committed to the success and innovation of your digital projects, among the best agencies in Paris. Our expertise in ergonomics, UX/UI design, interface design, web development, combined with our customer and user-centered approach, guarantees solutions that not only meet, but exceed your expectations.

We invite you to connect with our experts to discuss your ideas and see how we can make your vision a reality. Visit our website to further explore our services, our achievements and discover how we can support you in the first creation of your web application.


A web application project? Let's talk about it!

Do you want to chat in person?
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Quentin: 06 32 41 68 82
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Marouane El Gueddah

CEO of ADN Data

“By far the best agency collaboration”
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