Custom Development
We design custom web and mobile applications for organizations with complex business rules, critical integrations, and a need to deliver fast without compromising on quality.
When custom becomes essential
Standard solutions quickly reach their limits. Here are the contexts where our clients entrust us with their custom development projects.
Time-to-market is critical
You need to release an MVP in a few weeks to validate your market or gain a competitive edge. No-code tools are no longer enough; you need custom development designed to move fast.
Your business rules are unique
Complex workflows, specific calculations, pricing logic, regulatory compliance: no SaaS on the market can handle your core business. You need custom development precisely aligned with your processes.
You need to integrate a complex IS
ERP, CRM, ETL, legacy APIs, ESB, AI, IoT: your application must interact with a demanding ecosystem. Custom development allows for fine, secure, and maintainable integration over time.
You expect high volumes
High traffic, heavy processing, real-time, multi-tenant: your product must scale without breaking. A custom architecture is the only sustainable answer to performance requirements.
Security is non-negotiable
Sensitive data, GDPR, ISO 27001, regulated sectors (banking, healthcare, public): you need auditable, hardened, proprietary code, not a vendor black box.
Your current app is slowing down your growth
Technical debt, slowdowns, recurring bugs, slowed team: a custom rebuild becomes the only way to unblock your roadmap and restore velocity to the product.
The areas where we excel
When standard development is no longer enough, we handle the most demanding technical components.
IS Integrations & critical APIs
Connection to your ERP, CRM, ETL, ESB, banking services, legacy platforms. Clean management of REST, GraphQL, event-driven, and batch APIs.
ERP · CRM · APIsGenerative AI & intelligent agents
Business chatbots, RAG, LangChain agents, LLM integration into your workflows. From proof of concept to production with guarantees.
LLM · RAG · LangChainReal-time & high volume
WebSockets, streaming, message queues, microservices, event-driven architectures. For products that need to handle the load.
WebSocket · Kafka · ScalingMulti-tenant & SaaS platforms
Fine-grained management of roles, organizations, provisioning, billing, onboarding. We know how to build SaaS that scales.
SaaS · B2B · Multi-tenantTechnologies serving your project
No favorite tech : we choose the stack that meets your constraints in terms of performance, ecosystem, and team.
Langchain development agency
Voir la page technoWe never choose a technology out of habit. The right choice depends on your context: performance, existing ecosystem, internal skills, budget, and schedule.
Clear, precise, and immediately usable deliverables
Total control of your application, at every step.
You own 100% of your custom application.
We design solutions tailored to your use cases, without vendor lock-in or technical dependencies. At each sprint, you receive audited, documented, and deployable code.
This ensures a reliable, maintainable application capable of evolving alongside your business with us, or with any other team.
Documented specifications & architecture
Functional specifications, technical ADRs, data schemas. Everything is tracked.
Source code & documented APIs
Git repositories, Swagger / OpenAPI for APIs, operational READMEs for your teams.
Automated testing & CI/CD
Continuous deployment pipelines, measurable test coverage, production-like environments.
Functional demo at each sprint
Every 2 weeks, a live demo and a testable environment. You validate under real conditions.
100% proprietary code, zero lock-in
Full delivery of the code, with no vendor dependence or imposed black-box components.
Why our clients choose us (and stay)
No vague promises. Concrete, measurable, contractual commitments.
From scoping to production in 4 clear steps
An iterative, transparent process that delivers value from the very first sprint. No tunnel effect, no black box.
Scoping & architecture
Technical and functional scoping workshop, stack selection, architecture design, release plan, and precise estimation of sprint 1.
1 to 2 weeksIterative development
2-week sprints, functional demo at the end of each sprint, 24/7 accessible staging environment, automated tests at each commit.
2-week sprintsTesting & qualification
Unit, integration, end-to-end tests, security and performance audits. A contractualized quality matrix, not a marketing promise.
ContinuousProduction & AMS
Deployment, monitoring, skills transfer to your teams, or application maintenance with us. The choice is yours.
ContinuousReady to structure your custom project ?
Describe your needs. We will get back to you within 48h with a preliminary technical analysis and a detailed budget estimate.
The experts designing your custom project
Senior profiles, specialized in custom development.
Our areas of expertise
Frequently asked questions about custom development
How much does a custom development project cost?
The budget depends on the functional scope, technical complexity, and level of integration with the existing IS. A web MVP generally starts around
€30,000. A business platform with multiple integrations ranges between €80,000 and €250,000.
We provide you with a precise estimate after a 1 to 2-week scoping phase, which can be billed separately or included depending on the project.
How fast can you deliver a first MVP ?
Our 2-week sprint approach allows us to deliver a first functional MVP in 4 to 8 weeks depending on complexity. You test a usable version right from sprint 2, and we iterate until production release.
How do you choose the tech stack?
The choice of the stack is never made blindly. We decide based on your constraints: expected performance, integrations with your IS, skills within your teams, budget, schedule, and long-term maintenance strategy.
We master a wide spectrum of modern technologies: PHP/Symfony, PHP/Laravel, Node.js, Vue.js, React, Flutter, React Native, Lang Chain, etc.
How do you handle functional complexity ?
We systematically start with a scoping workshop that breaks down complex subjects into actionable blocks. For sensitive features (business calculations,
critical integrations, Al, performance), we mobilize dedicated senior profiles and prototype high-risk areas upstream.
Do you work with startups, mid-caps, or large enterprises ?
All three. We have supported startups in their initial developments, mid-caps in their digital transformation, and large groups on strategic projects with high security and compliance requirements.
Our method adapts to your maturity and constraints (purchasing, security, project governance).
What happens after production release?
Several options : Application Maintenance and Support (AMS) with us via a contractualized SLA, skills transfer to your internal teams, or a mix of both. An application lives and evolves, and we remain available for improvements and support over time.
Who owns the code once the project is delivered ?
It belongs 100% to you. This is written into our contracts. No hidden licenses, no imposed proprietary blocks, no technical lock-in. You can take the code and continue the project with any other team if you wish.
