1. My web application development services:

I develop your web application in part or in its entirety. This is my specialty and what I enjoy most. My extensive experience in all kinds of projects (startups, bootstrapping, and large companies) gives me a global vision to optimize the choice of technologies, development, costs, and maintenance according to needs. I also attach great importance to good development practices, particularly in terms of security, performance, and code structuring.

More than just outsourced development, I support my clients to build a successful application together.

• Development of an MVP (Minimum Viable Product)
• Development of new features
• Maintenance of an existing application
• Refactoring an existing application
• API Integration

2. When should you move to custom development?

A common question is when to move to custom development. Let's look at the different scenarios:

• 2.1 Caution
• 2.2 In the case of a simple, highly personalized project
• 2.3 After Wordpress
• 2.4 After no-code
• 2.5 For refactoring
• 2.6 Custom-made project with full knowledge of the facts

2.1 Caution

If you are not familiar with the software development industry, it is not advisable to start a complex project from scratch if you do not have an in-house IT team.

A common mistake is to call on a development agency at the very beginning of a project, providing overly ambitious specifications from the outset. It's certainly motivating to want to offer the market a new application with numerous features that will outperform the competition. However, if you do not have a substantial budget (IT and marketing), you will quickly be caught up in what is called technical debt on the one hand, and in the almost systematic underestimation of the cost of maintenance on the other, and all this without considering the suitability for the target market, which is never guaranteed.

2.2 In the case of a simple, highly personalized project

Custom development for a simple project is relevant when you want :

• A lightweight, fast site with no dependencies.
• Increased security.
• Complete control of the code.
• A virtually zero maintenance budget.

2.3 After Wordpress

Switching to custom-made is relevant when :

• WordPress hinders you more than it helps you (technical limitations, scalability issues, maintainability and technical debt, etc.).
• You want to differentiate yourself significantly from the competition with an innovative platform.
• You need a stable, scalable, internally controlled solution with a very specific UX/UI.
• Your website becomes a business application or a strategic lever for growth.

2.4 After no-code

• You've validated your market with a no-code platform and are looking to move on to the next step.
• For non-strategic features, using no-code is more than sufficient.
• On the other hand, if your added value relies largely on your platform, it's advisable to be independent with custom development.

2.5 For refactoring

• The project already exists, but with outdated technology or, through repeated additions and modifications, its structure has become unmanageable.
• In this case, refactoring all or part of the project makes sense.
• The proposed technologies are entirely appropriate.

2.6 Custom-made project with full knowledge of the facts

• It is not recommended to start from scratch on a complex project.
• But if you know exactly what you want and have already managed an IT project, then yes, custom development offers many advantages.

3. Types of projects

But what exactly is a web application? These are the main types of web applications, based on your trading model or logic:

1. ☁️ SaaS (Software as a Service)
   • Online software accessible via a browser, often with a subscription (monthly or annual).
   • The service is hosted and maintained by the provider.
   • Examples: Notion, Canva, Salesforce, etc.
   • A key model in B2B, scalable and profitable in the long term.
2. 🛒 Marketplace
   • Connects sellers and buyers (products or services).
   • The company takes a commission on each transaction or offers premium options.
   • Examples: Amazon, Airbnb, Vinted, Uber, etc.
   • Can be B2C, B2B, or C2C. The seller invoices the buyer, and the marketplace charges the commission to the sellers.
3. 🧩 Platform (multi-sided platform)
   • Provides a central infrastructure or service around which various stakeholders gravitate.
   • Can include SaaS, marketplace, content, API features, etc.
   • Examples: Stripe (payment), GitHub (developers + businesses), YouTube (creators + viewers + advertisers).
   • The network effect is essential here.
4. 🧾 Freemium / Premium
   • Offers limited free access, with advanced paid options.
   • Encourages rapid adoption, then conversion to a paying customer.
   • Examples: Spotify, Trello, Zoom, etc.
   • Very common for SaaS or productivity apps.
5. 📚 Content / Media (Content-based)
   • Relies on the publication of content: articles, videos, podcasts, etc.
   • Monetization via advertising, subscriptions, sponsorships, and merchandise.
   • Examples: Medium, Substack, Netflix (subscription), YouTube (ads + creators).
   • Can be freemium or paid only.
6. 🎓 E-learning / MOOC
   • Online course platform (standalone or live).
   • Monetization: pay-per-course, subscription, certification.
   • Examples: Udemy, Coursera, OpenClassrooms.
   • Can also follow a SaaS model for trainers.
7. 🧠 Social network / Community
   • Application focused on creating a network of users (friends, shared interests, etc.).
   • Monetization: advertising, premium subscriptions, sponsorships, integrated marketplace.
   • Examples: Facebook, LinkedIn, Reddit, Discord.
   • The network effect is essential here.
8. 🛠️ Infrastructure / API as a Service
   • Provides technical services in the form of APIs or tools to be integrated into other applications.
   • Primarily B2B model, often pay-as-you-go or subscription-based.
   • Examples: Twilio (SMS), Stripe (payments), OpenAI API.
   • High scalability, but technical development required.
9. 📊 Internal application (intranet / workflow / business)
   • To automate your business processes, customer interactions, etc.
   • Examples: banks, insurance companies, etc.
   • Part of an internal optimization strategy (efficiency, automation, error reduction, compliance).

4. Features

Here's a list of the key features found in most web applications of all types. This list can help you define your needs.

1. 🔐 Authentication & User Management
   • Account Creation (Registration)
   • Login / Logout
   • Forgot Password / Reset
   • Social Authentication (Google, Facebook, etc.)
   • Two-Factor Authentication (2FA)
   • Role / Permission Management
   • User Profile (Edit, Avatar, Preferences)
2. 📋 Dashboards & Navigation
   • Navigation menu (sidebar, topbar, etc.)
   • Customizable dashboard
   • Key information widgets or cards
   • Responsive view (mobile/desktop)
3. 📁 CRUD (Create, Read, Update, Delete)
   • Creating/editing/deleting entities (e.g., tasks, products, customers, etc.)
   • Searching/filtering/sorting
   • Pagination or infinite loading
   • Importing/exporting data (CSV, Excel, JSON)
4. 🛠 Process Management / Workflows
   • Statuses (in progress, approved, rejected, etc.)
   • Task or request assignment
   • Notifications/alerts (email, in-app, push)
   • Multi-level validation
5. 🧾 Advanced Forms
   • Dynamic/Conditional Fields
   • Client- and Server-Side Validation
   • Multi-Page or Step (Wizard)
   • Electronic Signature
   • File Upload
6. 💬 Communication & collaboration
   • Comment or chat system
   • Document or project sharing
   • Real-time notifications (WebSocket, polling)
   • @user mention / tagging system
7. 📈 Reporting & visualization
   • Charts, dashboards (KPIs, stats, etc.)
   • Time filters (day, week, month, etc.)
   • PDF or Excel export
   • Activity tracking or history (logs)
8. 💸 Payment & Billing (if applicable)
   • Integrates with Stripe, PayPal, and more
   • Invoicing/Quote Generation
   • Subscription/Auto-Renewal
   • Tax, Discount, and Currency Management
9. 🔧 Settings & configuration
   • User settings (language, time zone, theme, notifications, etc.)
   • Global application settings (business rules, access, etc.)
   • Multilingual management
10. 📦 Integrations & API
    • Inbound/Outbound Webhooks
    • Third-Party Integrations (Google Drive, Slack, Zapier, etc.)
    • REST or GraphQL API (Exposure or Consumption)
11. 🧪 Security & Compliance
    • Activity log (audit log)
    • Sensitive access management
    • Sensitive data encryption
    • GDPR: consent management, right to be forgotten
12. 📲 Mobile/PWA Specific Features
    • Offline operation (cache)
    • Push notifications
    • Installation on home screen (PWA)
    • Camera/geolocation access if applicable
13. 🛎️ Support and help
    • FAQ / Help Center
    • Chatbot or Integrated Support
    • Support Tickets / Help Desk
    • Feedback System
14. 📚 Specific business functions
    • Planning / Calendar (Google Calendar-like)
    • Maps / Geolocation
    • OCR, Document Analysis
    • AI / Smart Suggestions
    • All Kinds of Calculations

5. Software architecture

The vast majority of modern web applications separate the front-end from the back-end via a REST API. It has become a standard architecture, particularly in professional environments, for several reasons related to flexibility, performance and development organization.

Separating the front-end (user interface) and back-end (business logic and data management) in web application development has several advantages, both technical and organizational. Here are the main ones:

1. Better separation of responsibilities
   • The front-end focuses solely on display, interaction, and user experience.
   • The back-end focuses on data processing, business logic, authentication, database access, etc.
2. Better code maintainability
   • Each part can be modified independently as long as the communication API remains unchanged.
   • The code is more modular, making it easier to detect bugs, evolve, and update the project.
3. Improved scalability
   • The front-end and back-end can be deployed on different servers, or even scaled separately as needed (e.g., more load on the API than on the UI).
4. Independent technological choices
   • The front-end can be developed in Svelte, React, Vue, Angular, etc.
   • The back-end can use Spring Boot, Node.js, Django, Flask, etc.
   • This allows teams to choose the most suitable tools for each layer.
5. Facilitated collaboration between teams
   • Front-end and back-end teams can work in parallel, with a well-defined interface (REST API or GraphQL).
   • This speeds up overall development.
6. Reusability
   • The backend can be reused for other types of clients: mobile applications (iOS/Android), other frontends, third-party services, etc.
   • The frontend can consume other APIs if necessary (microservices, external services).
7. Enhanced security
   • The backend can be protected behind a firewall or other security measures.
   • The frontend provides access only to necessary functionality via API calls.
8. Better lifecycle management
   • The front-end (e.g., on a CDN) and the back-end (on a server or in the cloud) can be deployed or updated independently.

Definition: API stands for Application Programming Interface (interface de programmation d’application).

It is a set of rules (or “contract”) that allows two software or systems to communicate with each other, without knowing the internal details of the other.

There are a multitude of public or private, free or paid APIs that can be called from your own application in order to integrate external data or services in real time.

For example, you can call the Météo France website to get the weather forecast for the next few days for a given city. Or call another API to find out stock prices, or to get a list of all the films produced in 1983, to find out where a package is awaiting delivery, to integrate a payment gateway, etc.

6. Technologies

The technologies I am currently focusing on are:

6.1 For the back-end (Rest API)

I use Java with the Spring Boot framework and a PostgreSQL database.

Java continues to be solid choice for back-end development, thanks to its portability, scalability, solid performance, security, and rich ecosystem. Although new languages are emerging (like Go or Kotlin), Java remains a preferred option for companies looking to build robust, secure, and future-proof applications.

Thus, Spring Boot and Java form a very powerful duo for developing REST APIs. Thanks to its simplified configuration, native support for microservices, integrated security, and ability to adapt to modern architectures, Spring Boot allows for the development of efficient, maintainable, and rapidly scalable APIs. These advantages make it an essential choice for developers looking to create robust and high-performance back-end services.

Finally, PostgreSQL is a powerful and flexible open-source relational database. It offers excellent performance, reliability, and scalability, making it an ideal choice for back-end applications requiring robust data management.

This solution is particularly widely used by large enterprises.

6.2 For the front-end

Why I chose Svelte and Sveltekit ?

• Performance : Svelte produces faster applications with a smaller bundle size and better load times.
• Simplicity: The learning curve is gentler with Svelte, allowing for rapid application development without excessive complexity. This is an important factor for small and medium-sized businesses.
• Native responsiveness : Reactive state management is simple and intuitive, without the need for external libraries. No need for Redux (React) or Vuex (Vue.js).
• Better SEO and faster rendering: Thanks to server-side rendering (SSR) and static generation with SvelteKit. Native SEO support was also a key factor.
• Modern framework: Svelte is a newer but fast-growing framework. It is ideal for lightweight and fast applications, static sites, and projects where performance and simplicity are crucial.

7. Budget

Typically, the budget for a web application is calculated in workdays (8 hours/day). A quote is established for each application based on the development required, features, and specifications requested.

📂 Structure of a web application budget :

• Scoping / Specifications – X days
• UX / UI design – X days or separately
• Frontend development – X days
• Backend development – X days
• API / Third-party integrations – X days
• Testing / QA – X days
• Deployment / Delivery – X days
• Maintenance (optional) – monthly / quarterly
• Recurring technical costs – hosting, licenses, etc.

First and foremost, you need to define what the application does (and doesn't do). Therefore, before requesting a quote, it's advisable to clearly detail all the desired features in a document. The more comprehensive the document, the easier it will be to prepare an accurate quote.

💰 Cost estimation according to complexity

🟢 Simple application (5 to 15 days)

🟡 Medium Application (15 to 40 days)

🔵 Complex application (40 to 90 days)

8. Maintenance

Currently being written

9. Project stages

Currently being written