Full-Stack Software Engineer (React, NextJS) - Freelance (M/F)

Daily rate (TJM): 470€/day

CONTEXT

Our SaaS platform is in a key phase of acceleration and consolidation. In order to double our delivery capacity and ensure application stability before scaling up, we are reinforcing the technical team.

You will work in a pair with the developer already in place to integrate new business modules, deploy our behavioral tracking tools, and automate the quality control of the data displayed to users.

MISSIONS

• Co-develop and integrate API and UI components for our performance monitoring, pricing analysis, and commercial management modules.
• Integration of third-party tools & observability: implement the Medallia SDK for collecting user feedback.
• Set up application observability, performance monitoring, and behavioral analysis tools.
• Develop control mechanisms ensuring the consistency and reliability of metrics transmitted by the API and displayed on the UI interface.
• Automate validation processes (visual regression tests, E2E tests) to detect anomalies upstream and ensure the long-term stability of the platform.

TECHNICAL SKILLS

• Full-Stack: solid experience in creating/consuming APIs (REST) with a Back-end language (e.g.: Python) and mastery of a modern Front-end framework (e.g.: React, NextJS).
• Monitoring & tracking: experience in integrating third-party SDKs (e.g.: Datadog, Clarity, Medallia or equivalents).
• Quality & testing: mastery of testing practices (E2E, integration) and CI/CD automation.

BEHAVIORAL SKILLS

• Team spirit: working in a fluid pair with the existing developer (code reviews, pair programming, technical alignment).
• Product culture: working hand in hand with the Product Manager to transform functional needs into reliable components.
• Pragmatism: ability to deliver quickly while maintaining clean and maintainable code.
• Proactivity: ability to take initiative and propose suitable solutions.
• AI-Augmented Mindset: daily use of AI assistance tools to accelerate development and optimize code quality.
• Languages: professional English required (written and oral).

WORKING CONDITIONS

• Location: Lille
• TJM: 470€

1. Solid experience in creating/consuming REST APIs with a Back-end language (e.g.: Python)
2. Mastery of a modern Front-end framework (e.g.: React, NextJS)
3. Experience in integrating third-party SDKs (e.g.: Datadog, Clarity, Medallia or equivalents)
4. Mastery of testing practices (E2E, integration) and CI/CD automation
5. Team spirit: working in a pair, code reviews, pair programming, technical alignment
6. Product Culture: collaboration with the Product Manager to transform functional needs into reliable components
7. Pragmatism: ability to quickly deliver clean and maintainable code
8. Proactivity: taking initiative and proposing suitable solutions
9. Daily use of AI assistance tools to accelerate development and optimize code quality
10. Professional English required (written and oral)