Senior Software Developer Core and Platform

As a senior software developer, you'll contribute hands-on across the Jahia ecosystem, building and extending our codebases with your team and helping keep technical debt under control. You'll work closely with other senior engineers, tech leads and our CTO, share your perspective, and help address technical challenges pragmatically.

We embrace AI-assisted development (GitHub Copilot for everyone, access to all models) and we also have AI features on our roadmap (e.g. MCP server integrations and AI-driven search)-with a strong focus on real value, quality and security.

English language

We work in an international environment and English is our day-to-day working language (written and spoken): meetings, technical discussions, documentation, PR reviews, and cross-team interactions. Not everyone speaks French, so being able to communicate clearly and comfortably in English is essential. If English isn't at a level where daily collaboration feels natural, it's likely not going to work well for you or for us.

Role and responsibilities

Core platform & JavaScript rendering engine (server-side rendering in a Java backend)

You will work on critical runtime components: core platform services and our JavaScript rendering engine-at the intersection of Java and modern JS/TS, where performance, robustness, compatibility and developer experience matter.

In 2026, the team will drive significant modernization efforts for the next major version, aiming to simplify the platform and improve long-term maintainability and robustness.

• Develop features and fix bugs in Jahia's Java and JS/TS codebases .
• Participate in technical design discussions and trade-offs (quality, performance, maintainability).
• Review your team's PRs and help keep quality and technical debt under control.
• Help investigate and resolve complex customer/production issues with our Support team.
• Collaborate with Product and QA to deliver reliably (tests, automation, documentation when relevant).

Do you have experience in React?, * Strong experience as a senior software developer (typically 8+ years), with solid production experience in Java. OSGi experience is a plus.

• Solid understanding of JS/TS; React/TSX experience is a plus.
• Comfortable with code reviews, debugging, and writing maintainable code.
• Familiar with Docker/containerization and CI/CD pipelines/DevOps;
• Good team player. You'll be part of the Jahia family and this is important to us.
• Self-starter, quick learner and self-motivated.
• You are passionate about contributing to Open-Source projects

Our team is looking for passionate senior software developer to join our team in France. We have offices in Paris & Lyon and this role can also be full-remote from France. Jahia started its life as a CMS platform, and evolved since then into a digital experience platform (DXP) serving customers who either provide a public platform serving millions of unique visitors per year or built an extensive intranet used by thousands of employees daily. Our stack We are a Java & JS/TS shop, integrating some of the Apache Foundation's projects. Our core product (Jahia) relies on OSGi to extend its feature set through a wide set of applications and components (see ). On the backend side, our Java stack runs as a Java EE webapp embedding a Karaf OSGi runtime for modularity, on JDK 17 (migration to 21 is on the roadmap). We use JCR/Jackrabbit for content persistence and Lucene for indexing. The platform also includes a variety of internal services, user management, workflows, caching, scheduling, eventing (at varying levels of maturity). We support multiple rendering approaches: from legacy server-side rendering with JSP, to modern JS/TS server-side rendering inside our Java backend to build modern websites with TSX and React. We also expose GraphQL and REST APIs (JAX-RS/Jersey) for Headless CMS use cases, both of which can be extended through custom modules (e.g. Elasticsearch-backed search). Our front-end follows a micro-frontends approach: today (with a migration to coming), and React as our current UI library of choice. Jahia supports clustered deployments across multiple nodes for scalability, with distributed state and inter-node communication. Its modular architecture also provides a development ecosystem for integrators building custom modules to extend the platform. This extensibility makes quality and robustness critical, not only for Jahia's core services, but also for the modules we maintain and provide: authentication, external connectors, SEO, tooling, monitoring, and more. Jahia can be deployed on the cloud provider of our customers' choice, and we also build and operate Jahia Cloud, our PaaS, across multiple regions on AWS and OVH., At Jahia, we welcome change and innovation, nothing is set in stone, so you'll get to join a team of passionate developers and share your ideas on the future of our stack with your peers. What's in it for you? * Work in a creative, exciting and international company * Use a broad variety of cutting-edge tools, technologies and methodologies * Follow lightweight processes, defined collaboratively by the team * Beyond programming work, learn a business that is growing: digital experience management and marketing technologies We also love open-source, so you'll get a chance to contribute to the community!