Senior FullStack Developer
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
- Introductory call with HR — background, motivations, expectations.
- Technical interview with an R&D engineer, including a practical coding exercise.
- Head of Engineering interview — system design, long-term fit, and cultural alignment.
- 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.