Web and mobile development agency in Paris: custom websites, iOS/Android applications, SaaS platforms. Over 25 years of expertise. Quote within 48 hours.
DualMedia is a Paris-based agency specialized in web and mobile development custom development since 2000. Showcase websites, e-commerce platforms, iOS and Android applications, business SaaS, technical redesign, AI integration: our teams support SMEs, mid-sized companies, and large enterprises in the design, development, and maintenance of their digital products. By combining 26 years of web expertise and 17 years in mobile (since 2009), DualMedia masters the entire technology chain needed to deliver robust, performant, and scalable projects. Here is our approach to web and mobile development, our technologies, our methodology, and our client references.
Why choose DualMedia for your web and mobile development project
- 26 years of experience : founded in 2000, DualMedia has supported more than 1,000 digital projects since its creation
- Web AND mobile expertise : a multidisciplinary team covering both worlds, unlike agencies often specialized in only one
- Teams based in Paris : no hidden offshore, French-speaking contacts available
- Modern tech stack : mastery of 2026 technologies (React, Next.js, Symfony, Swift, Kotlin, React Native, Flutter)
- Native AI integration : our pipelines use Claude, ChatGPT, Cursor and GitHub Copilot to accelerate production without sacrificing quality
- Proven agile methodology : 2-week sprints, incremental deliverables, weekly reporting
- Long-term maintenance : most of our clients remain partners for more than 5 years
- Design + technical consistency : UI/UX design integrated into development, not in silos
Our complete web and mobile development offering
Custom web development
We design and develop all types of websites and plateformes web, from institutional showcase websites to complex business web applications.
- Showcase and institutional websites : business presentation, lead generation, branding
- E-commerce sites : Shopify, WooCommerce, Magento, PrestaShop, or custom headless solutions
- Plateformes SaaS : custom B2B tools, dashboards, customer portals
- Business web applications : custom ERP, internal tools, intranet, extranet
- Sites éditoriaux et médias : online magazines, high-traffic blogs, news sites
- Marketplaces : multi-vendor B2B and B2C plateformes
- Plateformes pédagogiques (LMS) : e-learning, online formation, certifications
Mobile application development
DualMedia has been developing native and hybrid mobile applications since 2009, with more than 200 apps delivered on the App Store and the Play Store.
- Native iOS applications : development in Swift / SwiftUI for optimal performance
- Native Android apps : development in Kotlin / Jetpack Compose
- Cross-platform apps : React Native or Flutter to optimize the budget
- Progressive Web Apps (PWA) : a lightweight and cost-effective alternative for certain use cases
- Apple Watch and Wearables apps : smartwatches, HealthKit integrations
- Event apps : apps for trade shows, conferences, festivals (since 2009, we have delivered more than 50)
- B2B business apps : field tools for sales reps, technicians, logistics
Backend, API and integrations
Every application needs a solid backend. We develop the server layers, databases, and integrations that power your products.
- REST and GraphQL APIs
- Microservices architectures
- CRM integrations (Salesforce, HubSpot, Pipedrive)
- ERP connectors (SAP, Sage, Odoo)
- AI integrations (OpenAI, Anthropic, Mistral)
- Payment systems (Stripe, Adyen, PayPlug)
- SSO and OAuth authentication
Maintenance, evolution, and hosting
A digital project doesn’t stop at launch. DualMedia supports its clients over the long term:
- Regular security updates
- Quarterly functional enhancements
- Performance monitoring and uptime (Datadog, New Relic, Sentry)
- Ongoing optimization of Core Web Vitals and technical SEO
- Managed hosting on OVH, AWS, Google Cloud, Scaleway depending on your needs
- Updates to Apple and Google stores for mobile apps
Technologies mastered in 2026
Mobile web development in 2026 requires balancing proven stacks and emerging technologies. Here is our toolbox.
Web frontend
| Technology | Preferred use |
|---|---|
| React + Next.js | Complex web applications, SaaS, highly interactive sites |
| Vue.js + Nuxt | An alternative to React for certain teams or needs |
| Astro | Editorial and marketing sites with maximum performance |
| SvelteKit | Projects requiring lightness and speed |
| HTML5, CSS3, Tailwind | Foundations of any interface, design tokens |
| TypeScript | For all medium- and large-scale projects |
Web backend
| Technology | Preferred use |
|---|---|
| PHP / Symfony | Business platforms, enterprise applications, custom e-commerce sites |
| PHP / Laravel | SaaS, APIs, mid-sized applications |
| Node.js / NestJS | Real-time APIs, microservices, AI integrations |
| Python / FastAPI | Data- and AI-oriented backends |
| WordPress | Editorrial sites and content marketing with a need for flexibility |
| Headless CMS | Strapi, Sanity, Directus for decoupled architectures |
Mobile
| Technology | Preferred use |
|---|---|
| Swift / SwiftUI | Native iOS, optimal performance, full access to Apple APIs |
| Kotlin / Jetpack Compose | Native Android, deep system integration |
| React Native | Cross-platform apps to optimize budget and timeline |
| Flutter | Cross-platform alternative with excellent visual rendering |
| PWA (Progressive Web Apps) | Lightweight solution, no store publishing, instant updates |
Infrastructure and DevOps
- Cloud : AWS, Google Cloud, Microsoft Azure, OVH, Scaleway
- Containers : Docker, Kubernetes for projects at scale
- CI/CD : GitHub Actions, GitLab CI, continuous deployment
- Databases : MySQL, PostgreSQL, MongoDB, Redis, Elasticsearch
- CDN and performance : Cloudflare, Fastly, optimization of Core Web Vitals
AI integration
In 2026, AI is no longer an add-on but a core component of most mobile web projects. DualMedia integrates:
- OpenAI APIs (GPT-5), Anthropic (Claude 4.7), Google (Gemini 2.5)
- Self-hosted open source models (Mistral, Llama)
- RAG pipelines with Pinecone, Weaviate, Qdrant
- Business chatbots connected to client documentation
- Document analysis, image recognition, audio transcription
Our 7-step development methodology
1. Scoping and needs analysis (1 to 3 weeks)
Scoping workshops with your teams, market research, analysis of technical and functional constraints, definition of business and user objectives. Deliverable: detailed specifications and costed roadmap.
2. UX/UI design and technical architecture (2 to 6 weeks)
Wireframes, high-fidelity Figma mockups, interactive prototypes, user journeys, server and database architecture. Client approval at every stage.
3. Development through agile sprints (2 to 12 months depending on scope)
2-week sprints with regular demos, Scrum methodology adapted to your team. Version-controlled Git code, dedicated staging environments, automated testing.
4. Testing, acceptance and debugging
Unit tests, integration tests, end-to-end tests (Cypress, Playwright), WCAG accessibility tests, performance tests, functional acceptance testing with your team.
5. Go-live and deployment
Deployment on cloud infrastructure, CDN configuration, implementation of monitoring, formation of your teams on the back office, publication of apps on the App Store and Google Play.
6. SEO and performance optimization
Technical optimization for organic search, analytics tracking implementation, improrment of Core Web Vitals, continuous optimization plan.
7. Maintenance and enhancements
Corrective and evolutionary maintenance contract, quarterly steering committee, enhancement roadmap, technology monitoring to anticipate obsolescence.
For what types of projects and clients
SMEs and startups
Do you have an idea and need a fast MVP product to validate your market? Our teams support startups from product scoping through go-live. Lean approach, MVP in 3 to 6 months, technical choices optimized for pivoting and growth.
Mid-sized companies and large enterprises
Redesign of your business platforme, technical migration, integration with your information system, complex governance with multiple stakeholders: our teams are used to enterprise projects. Contractual commitment, dedicated team, rigorous validation processes.
E-commerce and retail
Migration to Shopify or Magento, development of a custom headless site, ERP integration and real-time inventory, customer mobile application: we support DTC brands and traditional retailers in their digital transformation.
SaaS and software publishers
Are you launching a SaaS or evolving an existing platforrm? Our architectures are designed for scalability, recurring subscriptions, complex user roles, and integration with ecosystems (CRM, marketing automation, payment).
B2B business applications
Field apps for sales teams, route management applications for technicians, internal tools to optimize business processes: DualMedia designs and develops these custom tools while respecting your company’s IT constraints.
How much does a web and mobile development project cost in 2026
Budgets vary depending on complexity, but here are some indicative ranges to help scope your project.
| Project type | Budget range | Estimated timeline |
|---|---|---|
| Professional showcase website | 5 000 – 15 000 € | 4 to 8 weeks |
| Premium or multilingual showcase website | 15 000 – 35 000 € | 8 to 14 weeks |
| Mid-size e-commerce | 15 000 – 50 000 € | 10 to 16 weeks |
| Custom / headless e-commerce | 50 000 – 200 000 € | 4 to 9 months |
| SaaS platforrm (MVP) | 30 000 – 80 000 € | 3 to 6 months |
| Complete SaaS platform | 80,000 – 500,000 € | 6 to 18 months |
| Mobile application MVP (1 platform) | 25,000 – 60,000 € | 3 to 5 months |
| Complete mobile application (iOS + Android) | 60,000 – 200,000 € | 5 to 12 months |
| Custom B2B business app | 40,000 – 250,000 € | 4 to 12 months |
These ranges include UX/UI design, development, testing, deployment, and training. Maintenance is contracted separately (generally between 500 € and 5,000 €/month depending on scope).
Web and mobile development in 2026: what has changed
The profession has evolved profoundly over the past 3 years. Here are some major trends that we integrate into our projects:
AI is everywhere in the technical stack
Modern agencies use AI in their daily production: Cursor and Claude Code to accelerate development, ChatGPT for documentation, Midjourney for visuals. Client projects themselves are increasingly integrating AI features: business chatbots, content generation, data classification.
Mobile and web are converging
With PWAs (Progressive Web Apps), React Native, and Flutter, the web/mobile boundary is fading. A modern digital project often considers both worlds together, with maximum code sharing to optimize budgets.
Core Web Vitals and technical SEO are becoming critical
Google has strengthened the weight of Core Web Vitals (LCP, CLS, INP) in its ranking. Development that does not meet these thresholds from the design stage loses organic visibility.
GEO and AEO: a new discipline
Optimization for generative engines (Google AI Overviews, Perplexity, ChatGPT Search) has become a topic in its own right. 30 % of informational queries now go through LLMs.
Tighter security and GDPR requirements
The GDPR continues to become stricter, and the European AI Act adds constraints for projects using AI. Security best practices (OWASP audit, encryption, access management) are no longer optional.
A few DualMedia client references
Since 2000, DualMedia has supported major retail brands, ready-to-worar, major chains, festivals, photographers, production companies, startups, and public institutions. More than 1 000 projects delivered to date, in sectors as varied as retail, finance, tourism, education, culture, and healthcare.
Discover our client references
FAQ — Web and mobile development
What is the difference between web development and mobile development?
Web development concerns websites and applications accessible via a browser (Chrome, Safari, Firefox). Mobile development concerns applications downloadable from the App Store or Google Play, designed specifically for smartphones and tablets. The two can be combined via Progressive Web Apps (PWA) or cross-platform frameworks such as React Native.
How much does website development cost?
A professional showcase website costs between €5,000 and €15,000. An e-commerce website starts at around €15,000 and can reach €200,000 for custom platformes. A complete SaaS platforme can go up to €500,000. It all depends on the functional scope and integrations.
How much does a mobile application cost?
A mobile MVP on a single platforme (iOS or Android) starts at around €25,000. A complete application available on iOS and Android generally costs between €60,000 and €200,000. Custom B2B business applications can exceed €250,000.
How long does it take to develop a website or a mobile app?
A showcase website: 4 to 8 weeks. A mid-sized e-commerce site: 10 to 16 weeks. A mobile MVP: 3 to 5 months. A complete application or SaaS: 6 to 18 months depending on complexity.
Should you develop natively or cross-platform for mobile?
Native (Swift for iOS, Kotlin for Android) offers the best performance and full access to system APIs. Cross-platform (React Native, Flutter) cuts costs by 1.5 to 2 and speeds up development. The choice depends on the targeted performance, budget, and functional complexity. DualMedia provides scoping advice based on your case.
WordPress, Shopify, or custom development: which should you choose?
WordPress is excellent for editorial and content marketing websites that need flexibility. Shopify is unbeatable for a standard e-commerce site that is quick to set up. Custom development (Symfony, Laravel, Node.js) is essential when your business needs sort beyond the scope of packaged solutions: ERP integration, complex business workflows, unique user experience, massive scalability.
What are the legal requirements for a website in 2026?
GDPR (cookie banner, processing register, privacy policy), mandatory legal notices, digital accessibility (WCAG 2.2 level AA for the public sectoriel, recommended for the private sector), mandatory HTTPS, security against OWASP vulnerabilities. For e-commerce, terms and conditions of sale, the right of withdrawal, mediation, and marketplace regulations are added.
How can I guarantee the security of my website or application?
Regular OWASP audits, TLS encryption everywhere, forte authentication (2FA), granular permission management, regular and tested backups, intrusion monitoring, automated security updates, business continuity plan. DualMedia integrates these practices from the design stage, not as an afterthought.
Should maintenance be planned after going live?
Yes, absolutely. A website or app evolves in an environment that is constantly changing: browser and OS updates, evolving languages and frameworks, security alerts, regulatory changes. An ongoing maintenance contract (generally between €500 and €5,000/month depending on the scope) is essential to avoid rapid obsolescence.
Can you work with a technical team already in place?
Yes. DualMedia regularly works as an extended team, in partial subcontracting, or as occasional support on specific topics (redesign of part of a plateforme, integration of an AI feature, technical testing, security audit). Our teams adapt to your internal governance and processes.
How to choose a web and mobile development agency in Paris?
Check the track record (an agency created yesterday will be less reliable than an agency with 20+ years of experience), the reference portefolio, mastery of the target technical stack, the quality of the initial estimate (a vague quote is a bad sign), transparency about the methodology, and the ability to provide long-term support. Geographic proximity makes collaboration easier on long-term projects.
Start a web and mobile development project with DualMedia
Do you have a project, an idea to validate, a redesign to consider? Our project managers and architects support you from the very first conversation to define your needs, identify the best technical approach, and estimate your project.
Our commitment : a personalized response within 48 hours and free scoping for projects over €30,000.
DualMedia — Web and mobile agency in Paris — 76 Rue de la Pompe 75016 Paris — +33 9 67 63 18 87