Freelancer profile translated to English.
Back to original languageAbout Sébastien
Backend and architecture specialist, I combine deep technical expertise with a strategic vision of Fractional CTO. My role is to transform your technical challenges into performance levers, whether it's building new products or stabilizing existing ones.
🎯Why work with me?
🛠️My Areas of Intervention
1. Architecture & Backend (Core Expertise)
- PHP 8 / Symfony: Expert in API Platform, Doctrine, PHPUnit.
- Node.js: Proficient in NestJS for modular or microservices architectures.
- Design: Implementation of Clean Architecture and Domain-Driven Design (DDD).
2. Modernization & Scalability
- Technical audit, refactoring, and monolith migration.
- Performance optimization and management of high loads.
3. Ops, Infra & Data
- Containerization (Docker) and CI/CD pipelines (GitLab, GitHub).
- Complex database modeling and stream optimization.
✅Commitment & Long-Term Vision
I don't just execute; I act as a true partner in your success. My longevity on previous missions (up to 10 years) attests to my reliability and ability to evolve products long-term.
French
Native or bilingual
English
Fluent
Can work on-site
Marseille (up to 30km), Aix-en-Provence (up to 10km)
Experience
- Airbus HelicoptersDeveloperDEFENSE AND MILITARYJune 2025 - Today (1 year)Vitrolles, France
Development of Industrial Intelligence (BI & Reporting).
The challenge: Ensure the reliability, traceability, and analysis of massive data flows for aeronautical production management (High Availability).Strategic Achievements:
**Data Engineering & Query Builder**: Design of a dynamic search engine for generating custom queries. Modeling of high-performance data schemas to transform raw data into indicators.**Temporal Analysis System (Data Diff)**: Development of an innovative module for comparing industrial states. Implementation of a snapshot logic to identify real-time deltas (additions, modifications, deletions) over long production cycles.**Validation & Integrity Algorithms**: Creation of an advanced software layer for data validation (Data Quality). Deployment of algorithms to ensure data compliance, eliminating any risk of analysis errors.Real-Time Infrastructure: Implementation of a push notification system via WebSockets / Mercure, ensuring immediate responsiveness of operational teams to critical alerts on the production line.Technical Expertise:
- Backend: PHP 8, Symfony.
- Frontend: Angular (Interactive dashboards and data visualization).
- Data & Ops: Neo4J, Advanced SQL (query plan optimization), Complex algorithms, Docker, CI/CD.
- SONERGIAFullstack DeveloperMarch 2022 - Today (4 years and 3 months)Marseille, France
API Architecture & ERP Connectivity
Transformation of the information system through an API-First architecture.**Challenge**: Centralize and expose internal ERP business data to enable interoperability with third-party services and modern interfaces.**Achievements**:- Design of a scalable REST API using Laravel. The goal is to digitize the core application of an internal ERP.
- Development of a React administration interface.
Stack: Laravel, React, Eloquent ORM, Redis, Docker.Energy Premium Calculation Engine
Digitization of complex business rules and automation of regulatory processes.**Challenge**: Ensure the accuracy of calculations for renovation aid (MaPrimeRénov', CEE) by integrating changing and complex regulatory variables.Achievements:- Development of a high-precision calculation engine using Symfony, capable of interpreting complex decision trees based on beneficiary profiles.
- Design of a dynamic user journey in React (complex conditional forms) for audit data entry.
- Ensuring data integrity and implementing unit tests (PHPUnit) to validate calculation compliance with legal requirements.
Stack: Symfony, React, PostgreSQL, PHPUnit, Workflow Component. - FreelanceFullstack DeveloperJanuary 2013 - Today (13 years and 5 months)Aix-en-Provence, France
Fullstack Expert Consultant & Tech Trainer
Strategic support and delivery of complex business solutions.The challenge: Work on diverse ecosystems to design custom tools while imparting senior development best practices (Clean Code, Design Patterns).Notable Achievements:
**Industry & ERP (STMicroelectronics, Entre Marchands Auto)**:Design of industrial modeling software and an automotive ERP.Focus on modeling complex domains and optimizing transactional flows.**High-Audience Platforms (Inzejob, Marketplaces)**:Development of a job offer application and matchmaking solutions.Implementation of scalable architectures using Symfony and high-performance user interfaces with React.**HR & Management (Inzejob)**:Creation of human resources management tools centralizing employee data and administrative processes.**Training & Mentoring (Ynov)**:Leading software development training sessions.Mentoring rising talents on industry standards (Git, CI/CD, Testing).Technical Expertise:
Frameworks: Symfony (Backend Expertise), React (Reactive Interfaces).Methodologies: Agile, Code Audit, Skill Transfer.
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Education
- Information and communication technologiesAix-Marseille University