Freelancer profile translated to English.

Description

Full-stack Java/Spring Boot & React developer, I design, maintain, and stabilize production web applications.

I step in when there's a need to build a website or web app, add a feature, deliver a clean API, or take over a sensitive existing system — without breaking production.

My background

- ARTE (via REBAZE) — Spring Boot, hexagonal architecture, Next.js, SAML SSO

- Attijariwafa Bank — Secure REST APIs (JWT), KYC, high-volume batch processing

- Inetum — 2 years on the X7 software package, utility billing. Business applications for water & sanitation for local authorities — subscriber management, readings, interventions, billing, and business controls

- Sopra Banking — regulatory reporting, Cloud migration

Fixed-price projects

Websites & web applications (React/Next.js), feature additions, integrations (Stripe, API, IS), back-offices & dashboards, technical migrations (version upgrades, Docker, CI/CD), scoped MVPs in batches.

Staff augmentation

Backend Java/Spring Boot or Node/NestJS support on projects with complex business logic.

Stack: Java, Spring Boot, NestJS, TypeScript, React, Next.js, PostgreSQL, Oracle, Docker, CI/CD, hexagonal architecture, DDD, microservices, TDD.

Need a website, a feature, an API, or a system takeover? Contact me: yassineboulahnine.fr/book

Industry field of expertise

Languages

French
Native or bilingual
English
Native or bilingual
Arabic
Native or bilingual

Workplace preferences

Can work on-site

Paris (up to 50km), Lille (up to 50km), Nantes (up to 50km), Lyon (up to 50km), Bordeaux (up to 50km)

REBAZE
End client (Leading European media & audiovisual group)
TECH
January 2026 - Today (7 months)
Paris, France
Context: mission via REBAZE within a leading European media and audiovisual group — development and maintenance of critical business applications.
Intervention on critical business applications with Java Spring Boot backend development, Next.js interfaces, and strong functional logic. Work on a maintainable, testable, and structured foundation to facilitate evolution.
Streaming challenges on B2C and B2B solutions, SAML SSO, and Dashboards with optimized SQL queries.

- Java Spring Boot backend development with multi-module hexagonal architecture: strict separation of domain/application/infrastructure, enhanced testability and maintainability.
- Next.js frontend development: business interfaces, API integration, server-side rendering.
- Collaboration with business and technical teams on applications with strong functional logic.

Stack: Java, Spring Boot, Next.js, TypeScript, Jenkins, hexagonal architecture, Maven multi-module.

Mission carried out via REBAZE (confidential client).
Next.js Jenkins Java Spring Boot Hexagonal Architecture TypeScript
Attijariwafabank
Development Engineer — Java / Spring Boot / React (IT Department)
BANKING AND INSURANCE
October 2025 - January 2026 (3 months)
Paris, France
Context: data & compliance projects, internal tools in a banking environment.

Achievements:
Protectel integration via API: construction of XML requests and REST security via JWT.
Processing optimization: switching from "line by line" mode to batch mode (single / small batch / large batches) to handle high volumes (tens of thousands).
Development of Spring Boot REST APIs and integration with existing IS / external APIs.
Development of React interfaces for internal workflows (forms, validations, user journeys).
Modernization of legacy modules: technical refactoring, debt correction, stabilization, and performance improvement.
Automation of data/regulatory processes via Python (reduction of manual operations).
Participation in delivery: technical documentation, standardization of practices, production deployment.

Stack: Java, Spring Boot, React, Oracle SQL/PLSQL, Python, Docker, REST API.
Python React.js Automation Java Spring Boot Oracle PL/SQL
INETUM SOFTWARE FRANCE
R&D Engineer — Full-Stack Node.js / Express + React / Next.js (X7 Software Package)
DIGITAL AND IT
September 2023 - September 2025 (2 years)
Paris, France
Context: water/sanitation/billing business software package + field usage.

Achievements
• Modernization of Node.js / Express backend: refactoring, stabilization of critical flows, business logic optimization.
• React / Next.js front-end development: dynamic components, UX improvement, API integration.
• Implementation of Cypress E2E tests (reduction of regressions without a QA team).
• Contribution to Jenkins CI/CD (build, tests, automated analyses).
• Collaboration with R&D to stabilize and rationalize a historical technical foundation.

Stack: Node.js, Express, TypeScript, React, Next.js, Cypress, Jenkins, Docker, Oracle SQL.
Next.js Jenkins Docker Node.js PL/SQL