Arnaud D.

Following the stabilization of the critical C/C++ engine (phase 1), provided consulting services to manage the modernization and industrialization of Crédit Logement's IT department's web projects.

ARCHITECTURE

Initiated migration of Thymeleaf/JavaScript interfaces to React/TypeScript. Major refactoring of Java Spring Boot web services towards a clean MVC architecture, significantly reducing duplication and improving maintainability. Abstraction of the messaging layer: replaced direct IBM MQ coupling with a generic JMS interface, enabling multi-broker compatibility (IBM MQ/ActiveMQ). Designed a JMS stub service with ActiveMQ to isolate and test components independently. Migrated properties to @ConfigurationProperties, aligned with Spring Boot. Complete restructuring of the Maven ecosystem (centralized Super-POM, dependency modernization), preparing for JDK 17/Jakarta migration.

CI/CD & DEVOPS QUALITY

Full CI/CD implementation using CMake and GitLab CI to secure C/C++ deployments and monitor parallelism. Complete rewrite of Selenium/Cucumber tests (Fluent API, parallel execution). Significant increase in code coverage with Spring Test MockMvc and RestTemplate across all web services.

FUNCTIONAL EVOLUTIONS

Implemented new business requirements for REST web services and Thymeleaf/JavaScript user interfaces.

KNOWLEDGE TRANSFER & SUSTAINABILITY

Trained internal developers on the architecture, best practices, and implemented tools. Wrote comprehensive technical documentation for long-term maintainability.

► Recommended by the Project Manager and Engineering Manager (LinkedIn recommendations available)

🛠 Stack: Java, Spring Boot, Spring Test, GitLab CI, CMake, Maven, JMS, ActiveMQ, IBM MQ, Selenium, Cucumber, Thymeleaf, JavaScript, React, TypeScript

Critical intervention to resolve major performance and stability issues on Java web services, caused by the C/C++ back-end layer. The system suffered from memory leaks and a complete inability to handle simultaneous calls, paralyzing production.

STABILIZATION & PERFORMANCE (C/C++ & JAVA)

Diagnosed and corrected memory leaks in C/C++ code through low-level analysis (Valgrind, memory debugging), making the system operable under real-world load. Resolved concurrency issues (threads): identified race conditions and implemented synchronization mechanisms, enabling parallel request processing. Redesigned Java Spring Boot web services: optimized application layers, connection management, reduced response times.

ARCHITECTURE

Refactored web services towards a clean MVC architecture. Abstracted the messaging layer: decoupled IBM MQ via a generic JMS interface, enabling multi-broker compatibility (IBM MQ/ActiveMQ). Maven modernization: centralized Super-POM, preparing for JDK 17/Jakarta migration.

INDUSTRIALIZATION & QUALITY

Implemented CMake CI/CD with GitLab CI for C/C++ code: continuous integration, automated builds, parallelism monitoring. Significant code coverage on web services, Spring Boot UI, and Spring Batch tasks. Rewrote Selenium/Cucumber tests (Fluent API, parallel execution).

KNOWLEDGE TRANSFER

Trained developers on architecture, C/C++ specifics, and best practices. Technical documentation for the sustainability of critical fixes.

► This phase unblocked parallel processing in production and paved the way for complete modernization (2023-2025).

🛠 Stack: Java, C/C++, Spring Boot, Spring Batch, Hibernate, Maven, GitLab CI, CMake, IBM MQ, ActiveMQ, Valgrind, Selenium, Cucumber, Thymeleaf, JavaScript

Complete 'from scratch' redesign (v1 to v2) of the company tax consultation platform. Migration from a Java 6/JBoss legacy system to a modern Java 8/Spring Boot architecture within a team of 10 people.

PERFORMANCE IMPACT

Drastic reduction in response times: page load decreased from 3 minutes to 5 seconds through JSF/PrimeFaces Lazy Loading, Hibernate tuning, and PostgreSQL 10 stored procedure optimization.

ARCHITECTURE

Designed and developed the v2 application in Java 8/Spring Boot. Created REST and SOAP services with WSDL/JAXB serialization and @MapStruct mapping. Designed a dedicated Spring Batch service for CSV to PostgreSQL transfer (custom ItemReader/ItemWriter). SOAP/REST stub services with Spring WebMvc/OXM/Test. PostgreSQL 10 SQL stored procedures, Hibernate access rules. Spring 4/Servlet 3.0 configuration, Log4j/Spring AOP logging. Developed common J2EE 8 libraries.

TESTING STRATEGY (TDD)

Systematic TDD. JUnit 4/5, Spring MockMvc, Mockito tests. Maven Surefire and Failsafe. Coverage > 70% (SonarQube, EclEmma, JaCoCo). Fixed critical security vulnerabilities (SQL injections). Full Javadoc.

PERFORMANCE & DEVOPS

JProfiler campaigns leading to major optimizations. Automated JMeter tests integrated into CI to catch regressions before production. Jenkins Pipeline (Groovy), Shell Bash/Perl/Python scripts. Automated WAR deployments on Tomcat.

FRONTEND

JSF/PrimeFaces user interfaces, HTML, CSS, JavaScript, jQuery, Bootstrap.

KNOWLEDGE TRANSFER

Onboarding and training developers. Technical documentation. Systematic peer-reviewing, application releases.

🛠 Stack: Java 8, Spring Boot, Spring Batch, Spring WebMvc, Spring OXM, Spring Test, Hibernate, JSF, PrimeFaces, PostgreSQL 10, Jenkins Pipeline (Groovy), Maven, Docker, JProfiler, JMeter, Tomcat, Linux