Senior FullStack Developer

Paris
Who we are

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.
We work with major players in finance, defense, and telecommunications , delivering cutting-edge, quantum-safe security solutions.

On a daily basis, you will

As a Full Stack Developer, you will contribute to the development of DISCOVERY , our next-generation observability and orchestration platform for post-quantum cryptography operations.

You will work across the entire stack - backend services, data flows, and frontend interfaces - collaborating closely with product, backend, and infrastructure teams.
Feature Development & Architecture
  • 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.
Observability & Data Visualization
  • Implement advanced data visualization and monitoring features using the ELK stack (Elasticsearch, Logstash, Kibana).
  • Integrate backend logs, metrics, and analytics into frontend dashboards.
Engineering Excellence
  • Participate in code reviews and uphold high engineering standards.
  • Contribute to technical documentation and promote software craftsmanship.
  • Apply KISS, DRY, SOLID, and pragmatic engineering principles ("done is better than perfect").
DevOps & CI/CD
  • Contribute to deployment workflows, CI/CD pipelines, and automation initiatives.
  • Work with Docker/Kubernetes-based environments to ensure smooth delivery.
Requirements
The skills you'll need
Must-have
  • 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.
Bonus
  • 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.
The team you'll be joining

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.

Our recruitment process
  1. Introductory call with HR - background, motivations, expectations.
  2. Technical interview with an R&D engineer, including a practical coding exercise.
  3. Head of Engineering interview - system design, long-term fit, and cultural alignment.
  4. Offer & onboarding - welcome to CryptoNext!
Benefits
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.
Publié le 2025-11-15

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