Senior / Expert Java Backend Developer – Refactoring & Migration PHP to Java – AWS / GCP

Project overview

As part of a major IT system modernization program, one of our major clients is looking for a Senior / Expert Backend Java Developer to support the redesign and migration of several historical applications developed in PHP to a modern Java environment.

We are primarily looking for an excellent developer, passionate about technology, autonomous, responsive, and capable of quickly producing reliable, performant, and maintainable code.

The mission takes place in a demanding technical environment, with significant challenges in application modernization, software quality, and development industrialization.

Profile Sought

You ideally have at least 8 years of experience in software development, with particularly strong expertise in Java / Spring Boot.

You are above all an experienced developer, who continues to code daily and enjoys complex technical problems.

We are particularly looking for:

Will be particularly appreciated:

What Will Make the Difference

Beyond technologies, we are looking for a profile that stands out for its technical excellence, speed of execution, analytical skills, and high standards for code quality.

You enjoy understanding applications in depth, solving complex problems, and transforming historical systems into modern solutions.

A selection process including a technical assessment will be organized to validate development skills.

Work Environment

Within an experienced technical team, you will be involved in:

Technical Environment

Main Stack:

Cloud & DevOps:

Appreciated AI Tools:

The detailed environment and target technologies will be specified during discussions.

• Excellent command of Java and its ecosystem.
• Significant experience in back-end development and API design.
• Concrete experience in modernizing, refactoring, or migrating legacy applications.
• A strong culture of software quality, testing, and performance.
• A good understanding of modern application architectures.
• High autonomy and the ability to quickly understand an existing system.
• The ability to propose simple, robust, and effective solutions.
• Experience migrating PHP applications to Java.
• Dual Java / PHP skills.
• Practical knowledge of AWS and Google Cloud environments.
• Experience modernizing monoliths to modern architectures.
• Regular use of AI tools to improve development productivity.
• Analyzing and understanding existing applications developed in PHP.
• Redesigning and progressively migrating applications to Java / Spring Boot.
• Designing and developing new back-end components and REST APIs.
• Modernizing existing code and improving application architecture.
• Identifying and resolving performance, security, and maintainability issues.
• Implementing and improving unit and integration tests to secure migrations.
• Participating in code reviews and applying good development practices.
• Using AI development assistance tools to accelerate analysis, refactoring, testing, and documentation.
• Contributing to development industrialization and CI/CD processes.
• Java 11 / 17 / 21
• Spring Boot, Spring Framework
• REST API, microservices architecture
• PHP, Symfony / Laravel (knowledge appreciated)
• SQL, relational databases
• Git, CI/CD, Docker
• JUnit, Mockito, automated tests
• Clean Code, SOLID, good refactoring practices
• AWS (Amazon Web Services)
• Google Cloud Platform (GCP)
• Kubernetes, Terraform, Jenkins / GitLab CI/CD
• Claude Code
• OpenAI Codex
• GitHub Copilot or equivalent

Project details

• Start: ASAP
• Duration: 36 mois renouvelable
• Remote: hybrid
• Location: Île-de-France, France, FR
• Languages: French