Senior Developer

About CrossKnowledge

CrossKnowledge is a global leader in digital learning solutions, helping organizations develop their teams through engaging and scalable learning experiences. Our mission is to empower people and companies to grow through impactful learning technologies that align with real business needs.

Our engineering team in Sophia Antipolis plays a central role in building and evolving the platform that supports millions of learners worldwide. We’re looking for a skilled and motivated Senior Developer to join the core team, with a strong focus on maintenance and secure operations: owning production upgrades, patching dependencies (including security vulnerabilities), and providing L3/business priority support in close collaboration with Product, IT, and Technical Support.

The Role

As a Senior Developer, you'll work primarily with Symfony and PHP 8 to design, maintain, test and improve backend services. You’ll also collaborate on Python-based components and infrastructure.

You’ll be involved in maintaining and modernizing legacy systems, and you’ll contribute to technical discussions, mentoring junior developers, and coordinating with cross-functional teams like Product, IT and Technical Support.

The team works in a Kanban model, focusing on flow, fast feedback, and continuous delivery rather than fixed sprints. As a Senior Developer, you are expected to own work end-to-end: from design and implementation to testing, validation, and production readiness.

What We’re Looking For

• 5+ years of backend development experience, with strong expertise in Symfony and PHP 8.
• Comfortable working with and refactoring and validating legacy code.
• Strong database skills with MySQL.
• Ability to scope and estimate complex technical work, including identifying risks and cross-team dependencies.
• Strong sense of ownership and accountability for quality, including functional, regression, and non-regression testing.
• Comfortable working in a shift-left testing approach, where developers are responsible for validating their changes early and thoroughly.
• Enjoying solving complex problems using simple solutions.
• Professional proficiency in both French and English.
• Experience mentoring junior developers is a plus.
• Excellent written and verbal communication.
• Comfortable in multicultural, cross-functional teams.
• Able to present complex technical topics to non-technical audiences.

Additional skills (nice to have / a plus):

• Hands-on experience with AWS (e.g., EC2, S3, RDS, ECS).
• Proficient with Docker, Git and Kubernetes.
• Experience using Python and Bash for scripting or backend tasks.

Responsibilities

• Develop, test, and maintain backend services in Symfony/PHP, with full ownership from design to production.
• Own the testing phase of your deliverables (functional, regression, non-regression), in a shift-left approach, with QA support on tooling, strategy, and best practices.
• Participate in code reviews, CI/CD, and DevOps practices, ensuring quality and production readiness.
• Work with legacy systems and contribute to modernization efforts.
• Collaborate with product managers, IT, and technical support teams.
• Contribute to AWS-based infrastructure improvements.
• Support junior developers and promote knowledge sharing.

Perks & Benefits

• Competitive salary.
• Flexible working environment (up to 2 days of remote work per week).
• Health insurance and lunch vouchers.
• Opportunities for professional development and training.
• A strategic role impacting product quality and customer satisfaction.
• A culture that values quality, ownership, and improvement.

Tech Stack

• Languages: PHP 8 (Symfony), Python (Django)
• Databases: MySQL
• Tools: Docker, Git, Kubernetes
• Cloud: AWS (EC2, S3, RDS, ECS)
• Methodologies: Kanban(flow-based delivery), CI/CD, peer reviews, shift-left testing

Why Join Us?

At CrossKnowledge, you’ll work on meaningful projects that impact learners and organizations globally. We foster a culture of continuous improvement, collaboration, and respect.

You'll be part of a passionate team of 30 engineers based in Sophia Antipolis, working with modern tools and real technical challenges. You’ll work in a team that values quality, autonomy, and end-to-end ownership, where developers play a key role in ensuring reliability and customer trust.