Your custom software delivered to production every week for a fixed budget.
15 days to form your own opinion. No invoice if the result does not suit you.
They trusted us
DEVEDANOS is a custom software development agency founded by Sébastien Nobour, available in Maastricht (Netherlands) and Versailles (France), specializing in Continuous Delivery and agility. The agency builds custom web applications (SaaS, marketplaces, e-commerce, CRM, internal tools, AI integration) primarily in React.js, Node.js, and TypeScript for mid-market companies across Europe and the United Kingdom. DEVEDANOS operates on a monthly subscription model with weekly production deployments, a trial period, a fixed monthly budget with no amendments, and a contractual zero-regression guarantee.
Custom software development in numbers
52.1%
of projects exceed their planned budget
2/3
of feature improvements generate no measurable value
3-4x
more expensive to maintain than to develop
And yet, the same methods persist. The word ‘agile’ has become a sales pitch rather than an engineering discipline.
Sources : Flyvbjerg, How Big Things Get Done, 2023 (16,000 projects) · Kohavi et al., Microsoft Research, 2009 · Applied Software Measurement, Capers Jones
Software development: the traditional approach vs. ours
The traditional approach
Your quote is based on estimates. On average, actual cost exceeds the estimate by 80%.
Our approach
Your monthly budget is defined together and known before we start. Paid at the end of the month for priority features you have tested and approved.
The traditional approach
You wait months before seeing the software work
Our approach
You test the real application yourself, from the very first weeks.
The traditional approach
A change in priorities triggers an amendment and additional costs
Our approach
You change direction whenever you want. Every adjustment is included, without amendment or extra cost.
The traditional approach
A fixed bug reappears three months later. You pay again.
Our approach
Zero-regression guarantee: every bug fix comes with an automated test. It will never reappear.
The traditional approach
The more features you add, the slower and more expensive the next one becomes. The software turns into a burden no one wants to touch.
Our approach
Every feature we deliver leaves the software easy to modify and in a working state. Adding the tenth feature is as fast as adding the first.
From development to strategy, this is what we do best
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SaaS
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Dashboard
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CRM
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E-commerce
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Client Portal
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Business Application
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Marketplace
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Job Board
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Back-office
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Services Platform
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Social Network
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Monitoring
AI Integration
Software Architecture
DevOps Services
Legacy Modernization
Mobile App Development
Software Consulting
Agile Coaching
Web Application Development
Start your custom software development with DEVEDANOS
Discovery call
We discuss your project, your challenges and your goals. If we believe we are the right partner, we present our offer, the framework agreement and the quote.
Build
We specify, develop and you test every feature. The first 15 working days are a trial period: not convinced, no invoice issued. The zero-regression guarantee applies from day one.
Production deployment
We deploy what you have tested and approved. Once in production, we monitor for unexpected behavior so problems are detected early and fixed fast. Maintenance (corrective, adaptive, preventive) is built into the delivery cycle. Then we start again. Specification, development, acceptance testing, deployment, continuously.
"He brings a strategic vision that goes far beyond the purely technical aspects of a product. His ability to understand broader challenges, whether related to user experience, business strategy, or long-term scalability, makes him invaluable. Tortuga would never be what it is today without his help."
Corentin Teulet, Founder — Tortuga
You test continuously
Permanent access to a demo environment. You test and approve every feature yourself.
Change direction freely
Shift priorities at any time, with no amendment and no extra cost. Your roadmap stays yours.
Zero-regression guarantee
Every bug fix comes with an automated test. It will never reappear.
Trusted by ambitious teams, and here is what we delivered together.
2024La Suite Territoriale / Digital Services Platform
Contributed to the development of La Suite Territoriale for France's National Agency for Territorial Cohesion, a digital services platform for local governments.
30 beta testers in 6 months
2024WeekandGO / Marketplace
Developed the booking module and search engine of WeekandGO for Groupe Rapido, a flash-sale travel marketplace.
3M unique visits per year
2025Match'Up / Job Board
Contributed to the AI module of the Match'Up platform for OMNES Education, automating student-company matching through AI integration.
80% time reduction through AI integration
Why Choose Us
Process transparency, flexibility, and software quality: the pillars of our subscription model.
Fixed Monthly Fee
Your monthly budget is defined together before we start. No amendments, no hidden fees.
Change Direction at No Extra Cost
Change priorities anytime. The contract requires no amendment and no extra cost, and the software is built so that changing direction stays fast.
Zero-Regression Guarantee
Every bug fix comes with an automated test. It will never reappear. Corrective, adaptive, and preventive maintenance is included in the subscription.
Trial Period
15 days to form your own opinion. No invoice if the result does not suit you.
No Middlemen
The person who designs your system, writes the code, and deploys it to production is your point of contact.
Stay Because You Want To
Cancel whenever you want, with no penalty. Your software is always in a working state because we maintain it continuously, so you are never waiting on a future delivery to get something usable.
We have worked with the very best and here is what they say.
- Thibaud Chambert-Loir Project Manager, ANCT
Sébastien stayed focused on product quality and user value, despite a complex and highly political working environment.
- Julien Francisco Business Analyst, OMNES Education
His rigor, his ability to listen, and his strong involvement in understanding functional needs to translate them into effective and maintainable solutions. Clean, clear, and well-structured code.
A Clear, Predictable Model
A monthly subscription. Everything included. No surprises.
Monthly subscription
Fixed monthly budget defined together
The budget is defined during the discovery call. Invoiced at the end of the month. Cancel anytime.
- You test and approve before every release
- No budget wasted on features nobody uses
- Nothing breaks: every release passes automated tests
- Your customers see results every week
- Maintenance included, no separate contract
- You talk to the person who builds it
15 days to form your own opinion. No invoice if the result does not suit you.
Frequently asked questions
What is custom software development by subscription?
A model where you pay a fixed monthly budget for continuous development. The budget is defined together before you start, the scope adapts to what you learn. You change priorities at any time, with no amendment.
How long does it take to develop custom software?
At DEVEDANOS, you use the software in real conditions from the very first weeks. Working software is the primary measure of progress. Our Continuous Delivery discipline allows us to ship features continuously. Waiting months for a full delivery, or following demonstrations that show what progresses without showing what does not work yet, only delays the moment you get the answer to this very question.
How does the collaboration work?
Custom software development works like the relationship between an author and a printer. You know your business and your users. We master software engineering. Your involvement is essential: acceptance testing of features, regular feedback, priority decisions. Without that, no provider can deliver software that matches your needs.
What happens if I am not convinced after the trial period?
No invoice issued. The trial period lasts up to 15 working days. The produced code remains the property of DEVEDANOS.
What happens if a bug appears?
Three cases must be distinguished. A regression (a feature you had tested and approved behaves differently after a change): our zero-regression guarantee applies, we fix it and add an automated test that prevents its reappearance. A defect found during acceptance testing (the delivered behavior does not match what you expected): either the specification we prepared together contained an error, or the feature does not respect the specification. In both cases, the work is not finished, we finish it. A behavior change requested on a feature already tested and approved: that is an evolution, not a bug.
How do you guarantee software quality?
We work in small steps. Each feature is specified with you, built, tested, and deployed individually. Because each step is small, defects are spotted fast and fixed fast. Automated tests verify the expected behavior with every change we make. You test the real application yourself and confirm each feature does what you need. In production, monitoring detects unexpected behavior early. And our zero-regression guarantee means every bug fix is locked in by an automated test: once fixed, it stays fixed.
How do you guarantee a usable application in a few weeks?
An application is not a monolithic block, but a set of independent features. The Manifesto for Agile Software Development and lean principles push us to prioritize high-value features from the start. Each feature is specified, developed, tested, accepted and deployed individually. Our Continuous Delivery discipline guarantees easily modifiable code, quickly adaptable to new needs, and an application in a working state at all times. That is what allows us to deliver usable applications from the first weeks, in just a few features.
When does development actually start?
As soon as the quote is signed. We run a framing workshop to identify what will generate the most value for your users (Impact Mapping, OKRs, prioritization). Two options depending on your preference: collaborative or delegated. You get a clear direction from the first week. Development starts immediately after.
What types of software do you build?
Web applications, SaaS platforms, marketplaces, e-commerce, job boards, custom business software, CRM, monitoring, client portals, admin consoles and AI integration into existing applications.
How much does custom software cost?
No reliable tool exists today, according to scientific research, to estimate the cost of developing software. Estimates systematically turn out wrong, and the vaguer the project, the higher the quote. But software is not a monolithic block. It is a set of independent features, and that reality changes everything. Since each feature can be specified, developed, tested and delivered individually, the real question becomes: what to deliver first to alleviate your problem as fast as possible? That is exactly what Continuous Delivery, lean and agility enable. At DEVEDANOS, you pay a fixed monthly budget for delivered features that you have tested and approved. The more we add, the more your problem recedes, with the long-term prospect of solving it entirely. We build this budget with you during the discovery call.
Does the trial period apply to all projects?
The trial period lasts up to 15 working days. During this time, the source code remains hosted on our systems. If you request access to the code before the end of the period, the trial ends and invoicing is due at the end of the month, payable within 15 days.
Ready to see the difference? Talk directly to the developer who will work on your project.
No commitment. Let’s talk about your situation.