Senior FullStack Developer

Cryptonext Security; Paris; Hybride; EUR 80 000 - 100 000; Plein temps

Résumé du poste

A deeptech cybersecurity startup in Paris is seeking a Full Stack Developer to enhance its DISCOVERY platform for post-quantum cryptography operations. The role involves full-stack feature development, API design, and collaboration with cross-functional teams. Ideal candidates possess over 10 years of development experience, strong skills in Node.js and React, and a master's degree from a recognized engineering institution. This position offers flexible remote work options and competitive compensation aligned with expertise.

Prestations

Flexible remote policy

Competitive compensation

Challenging engineering problems

Qualifications

• 10+ years of experience in software development, ideally in a software editor or deeptech environment.
• Strong hands-on expertise in modern JavaScript frameworks.
• Strong understanding of Docker and containerized deployments.
• Fluent in English.

Responsabilités

• Contribute to the development of DISCOVERY platform for post-quantum operations.
• Design and maintain full-stack features integrating frontend and backend technologies.
• Implement advanced data visualization and monitoring features.

Connaissances

Node.js

React

TypeScript

Docker

Kubernetes

Kafka

ELK stack

CI / CD practices

Formation

Master’s degree from a French engineering school or European equivalent

Outils

Git

Description du poste

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.