Freelancer profile translated to English.
Back to original languageAbout Alexandre
Looking for a trusted developer for your mobile application? You've come to the right place.
In a nutshell:
I develop custom mobile applications for various sectors (Fintech, health, catering, oenology, travel, etc.).
📱 React Native & Expo Mobile App Developer (iOS & Android), I design and publish performant, reliable, and scalable mobile applications. My dual mobile + backend (Symfony) profile is an asset: I manage your entire mobile application chain, from the API backend to store publication.
🎯 What I do:
React Native mobile app development with Expo (iOS & Android)
Creating mobile apps from scratch or taking over existing React Native / Expo projects
Advanced mobile features: biometric authentication, push notifications, in-app payments, geolocation, offline mode
Custom backends for your mobile applications (Symfony, REST API, JWT)
Integration of third-party APIs: Stripe, Treezor, Bridge, Firebase, analytics…
Publication on the App Store and Google Play
Maintenance and evolution of your iOS and Android apps
💼 Types of mobile applications:
Fintech: iOS/Android banking apps, KYC, transactions, aggregation
Mobile E-commerce: catalogs, payments, customer areas
Business Tools: dashboards, monitoring, internal apps
SaaS: React Native / Expo interfaces connected to web ecosystems
🚀 My approach:
I don't just code an app. I help you build a real product mobile application, with clean, maintainable code, designed to last on both iOS and Android.
🤝 How we work:
☎️ Intro call to understand your mobile app project
📄 Clear quote
🔄 React Native / Expo development with iterative deliveries
🚀 Publication on the App Store and Google Play
🗓️ Long-term availability for maintenance
✅ Available on a daily rate or fixed-price basis for your iOS and Android mobile app projects with Expo
French
Native or bilingual
English
Fluent
Remote only
Primarily works remotely
Experience
- BookTalkMobile Application for Readers (React Native (Expo) & Real-Time)CULTUREFebruary 2025 - Today (1 year and 6 months)Lille, FranceTechnical Achievements
- Mobile Development (React Native Expo): Design of a cross-platform application (iOS/Android) with a fluid, near-native experience and a user-centric interface.
- Backend Architecture (Symfony & Node.js): * Symfony API: The core of the application for business logic, security, and data persistence.
- Real-Time (Node.js & Socket.io): Implementation of an instant messaging server to allow readers to chat live without latency.
- Notifications & Asynchronism: Use of the Symfony Messenger component for asynchronous push notification processing, ensuring maximum application responsiveness even under heavy load.
- API & Data Integration: Connection to the Google Books API for automatic retrieval of metadata (covers, summaries, authors) and management of massive libraries.
- Monetization System: Implementation of a paid subscription system with management of premium access and transaction security.
Project ImpactMaximum Interactivity: A fluid instant chat enabling the creation of a truly active community.Scalability: Separation of responsibilities (PHP for data, Node.js for streams) allowing support for a growing number of simultaneous users.Premium Mobile Experience: A stable, notifiable, and monetizable application from day one. - ToneofirstSymfony Backend Architect: Core Banking & BaaS MiddlewareBANKING AND INSURANCEAugust 2024 - August 2025 (1 year)Lille, France
BaaS Integration: Core Banking & Xpollens Gateway (Symfony)
I led the development of a strategic middleware connecting a proprietary Core Banking system to the Xpollens ecosystem. The goal was to eliminate manual intervention by automating the entire lifecycle of accounts and payment flows.Technical Expertise & Architecture- API & Middleware Architecture: Design of a REST interface under Symfony, optimized for real-time synchronization of Core Banking data with external banking services.
- Financial Flow Processing: Orchestration of events (transfers, card payments) via Webhooks. I used Symfony Messenger with RabbitMQ to ensure transaction resilience and asynchronous processing without data loss.
- Security and Compliance (PSD2): Implementation of rigorous security protocols, including mutual authentication (mTLS) and request signing (HMAC). The project also includes encryption of sensitive data (PII) and the establishment of audit logs essential for bank reconciliation.
- Business Automation: Full integration of onboarding workflows (KYC/KYB) and instant synchronization of account statuses.
Results AchievedThe implemented infrastructure has automated 100% of payment flows, eliminating manual data entry errors. The system is now capable of handling high load peaks while maintaining a transactional processing time in the millisecond range. - B PartnerB Partner: Creation of a Neobank from A to Z (Paynovate BaaS)BANKING AND INSURANCEApril 2024 - August 2024 (4 months)Lille, FranceArchitecture and development of a complete banking solution integrating Paynovate's infrastructure. A complex project combining back-end robustness and front-end fluidity (decoupled architecture).Technical Achievements
- Headless Architecture (Symfony & Next.js): * Back-end: Development of a REST API under Symfony to orchestrate business logic and secure communication with the BaaS.
- Front-end: Creation of a high-performance customer interface with Next.js, offering a fluid (SPA) and secure user experience.
- Paynovate BaaS Integration (Core Banking): * Account & Balance Management: Real-time synchronization of balances and account statements.
- Financial Flows: Automation of transactions (SEPA transfers, direct debits) with payment status management.
- IBAN Generation: Dynamic and secure generation system for bank details.
- Security & Authentication (OTP): * Implementation of strong authentication (2FA / OTP) for validation of sensitive operations (PSD2).
- Securing inter-API exchanges through signature and encryption protocols.
- Monitoring & Audit: Implementation of comprehensive transactional logs to ensure traceability and facilitate bank reconciliation.
Project ImpactRecord Time-to-Market: Launch of a functional neobank by leveraging an API-First architecture.Reliability: 0% data loss on transaction flows thanks to rigorous queue management.User Experience: A modern and responsive interface allowing users to manage their finances without latency.
Reviews
Guillaume
SUPERTAG EURL
Reviewed on 3/24/2025
The project we worked on with Alexandre was complex and the end client's expectations were very demanding. Despite some minor delays, the initial brief (and even more) was fully met. Alexandre is a seasoned, involved developer who relentlessly sought solutions to every unexpected problem I encountered. Despite the urgency and pressure, Alexandre always remained pleasant and available. I highly recommend him.
AD
Account deleted
Reviewed on 11/9/2018
Very good exchange with Alexandre, the final work meets expectations. I therefore recommend his work!
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Education
- BTS in Digital Systems, IT, and NetworksLycée Jean-Rostand2017
- Professional Bachelor's Degree in Data Analysis and Industrial InformaticsIUT A Lille 12017