Senior FullStack Developer

You will work across the entire stack - backend services, data flows, and frontend interfaces - collaborating closely with product, backend, and infrastructure teams., * Design, develop, and maintain full-stack features for the DISCOVERY platform.

• Build modern, responsive React front-ends integrated with Node.js and Kafka backends.
• Participate in architectural decisions and propose technical improvements aligned with long-term product vision.

Backend Engineering & APIs

• Design and implement REST and event-driven APIs.
• Ensure performance, scalability, and resilience across distributed components.
• Collaborate with backend engineers on domain modeling, API contracts, and data flows., * Implement advanced data visualization and monitoring features using the ELK stack (Elasticsearch, Logstash, Kibana).
• Integrate backend logs, metrics, and analytics into frontend dashboards., * Contribute to deployment workflows, CI/CD pipelines, and automation initiatives.
• Work with Docker/Kubernetes-based environments to ensure smooth delivery., You will join the R&D engineering team behind the DISCOVERY platform, collaborating with:
• Backend engineers
• Product managers
• Platform and infrastructure engineers
• The Head of Engineering
• Cryptography experts and system engineers across the company

You will play a key role in shaping the architecture, user experience, and technical foundations of the DISCOVERY product.

Do you have experience in gRPC?, Do you have a Master's degree?, * 10+ years of experience in software development, ideally in a software editor or deeptech environment.

• Master's degree from a French engineering school or European equivalent.
• Strong hands-on expertise in:

• Node.js
• React
• TypeScript

• Strong understanding of Docker, Kubernetes, and containerized deployments.
• Experience with message-driven architectures (Kafka or equivalent).
• Solid understanding of the ELK stack and its application in observability/analytics contexts.
• Comfortable with CI/CD, Git workflows, automated testing, and modern DevOps practices.
• Deep grasp of software design principles and maintainability.
• Fluent in English., * Experience with gRPC or other microservice communication patterns.
• Secure coding practices and application security awareness.
• Experience with performance-critical or network-intensive systems.
• Background in cybersecurity or cryptographic systems.
• Experience with AWS, GCP, or Azure.

What's in it for you at CryptoNext

• Join a fast-growing deeptech company at the cutting edge of quantum-safe cybersecurity.
• Work on challenging engineering problems using modern technologies.
• Build next-generation observability tools for cryptographic operations.
• Flexible remote policy + office in central Paris.
• Competitive compensation aligned with your seniority and expertise.
• Direct impact on the future of secure communications.

CryptoNext Security is a deeptech startup specializing in post-quantum cryptography. We help institutions and enterprises prepare for a future where quantum computers will break current cryptographic standards.