Senior Back-end Developer C# .NET in Tremblay-en-France, Île-de-France at Jobgether

This position is posted by Jobgether on behalf of a partner company. We are currently looking for a Senior Back-end Developer C# .NET in France.

You will join a fast-evolving digital content environment where back-end engineering plays a central role in delivering scalable, high-performance services to millions of users worldwide. As part of a senior technical team, you will contribute to the design, development, and optimization of robust APIs and core back-end systems that power a personalized reading experience across multiple platforms. The role offers a strong focus on architecture, performance, and reliability in a product-driven organization. You will collaborate closely with engineers, product teams, and cross-functional stakeholders in an agile and innovation-oriented setup. This is an opportunity to work on impactful systems that support large-scale content distribution while continuously improving technical quality. The environment values autonomy, technical excellence, and continuous learning.

• Design, develop, and maintain scalable back-end services and APIs using C# and .NET Core.
• Ensure the performance, reliability, and security of existing systems while contributing to their continuous evolution.
• Participate in system architecture design and technical decision-making for back-end solutions.
• Implement unit tests, follow coding standards, and ensure high-quality code through regular code reviews.
• Work within an agile development environment, collaborating with cross-functional teams to deliver features efficiently.
• Contribute to CI/CD pipelines, version control practices, and development tool improvements.
• Optimize system performance and ensure adherence to best practices in software engineering.
• Conduct ongoing technological monitoring to identify new tools, frameworks, and solutions that can enhance the technical ecosystem.

• Strong expertise in C# and .NET Core development.
• Solid experience with SQL databases and data modeling.
• Good knowledge of REST APIs and/or gRPC architecture.
• Experience with CI/CD pipelines, source control systems, and modern development workflows.
• Strong background in performance optimization, unit testing, and software engineering best practices.
• Product-oriented mindset with the ability to align technical decisions with business needs.
• Strong collaboration skills and ability to work effectively within cross-functional teams.
• Fluency in both French and English.
• Ability to work independently in a fast-paced, agile, and evolving environment.

• Freelance contract opportunity until end of December 2026.
• Fully remote working arrangement within France.
• Opportunity to work on high-traffic, large-scale digital platforms.
• Exposure to modern back-end architectures and cloud-ready systems.
• Agile and collaborative international working environment.
• Strong technical culture focused on quality, innovation, and continuous improvement.
• Opportunity to contribute to impactful product experiences used by millions of users.