Senior Data & Platform Engineer

• Define and maintain the end-to-end data model for COMPASS (entities, relationships, vocabulary, lifecycle).
• Translate product requirements into robust database schemas, indexing strategies, and normalization/denormalization choices.
• Ensure semantic consistency and data governance rules across all services., * Design, validate, and maintain ingestion pipelines using Kafka, ensuring data correctness and consistency.
• Define the canonical formats exchanged across Kafka (ingestion), PostgreSQL (storage), and Elasticsearch (search).
• Validate and standardize data structures produced by probes, sensors, and backend services.

Backend Collaboration & API Contracts

• Work closely with backend teams to design API-level data contracts aligned with the data model.
• Optimize queries, indexes, and persistence strategies for real-time workloads and analytics., You will work closely with:
• The R&D engineering team building CryptoNext's cryptographic and observability products.
• Backend engineers designing APIs and distributed services.
• The Head of Engineering and CTO for architecture, strategy, and long-term product evolution.
• Product and QA teams to ensure data quality, reliability, and consistency across the platform.

You will be the reference person for all data-related decisions and architecture within the COMPASS squad., * Technical Interview with a senior engineer and the Head of Engineering (Kafka, PostgreSQL, ELK, data modeling).

• CTO Meeting - deep dive on architecture, COMPASS roadmap, and cultural fit.
• Offer & onboarding - welcome to CryptoNext!

Do you have experience in Schematics?, Do you have a Master's degree?, * 15+ years of experience in software or data engineering in a distributed or complex environment.

• Master's degree from a French engineering school or European equivalent.
• Deep expertise in:

• Data modeling & relational schema design
• PostgreSQL administration & performance optimization
• Kafka (setup, topics/partitions, consumer groups, schema registry, monitoring)
• Elasticsearch / ELK stack

• Strong hands-on experience with:

• Stream processing architectures
• ETL/ELT workflows
• Data lifecycle management

• Proven ability to design data flows with clean, contract-based schemas.
• Strong commitment to code quality, documentation, and operational reliability.
• Fluency in English., * Experience with ClickHouse, Grafana, or Prometheus.
• Understanding of secure data handling and cryptographic components.
• Familiarity with AWS/GCP or hybrid on-prem architectures.
• Background in cybersecurity, observability, or high-throughput systems.
• Experience with large-scale data retention strategies and analytics workloads.

CryptoNext Security is a deeptech startup specializing in post-quantum cryptography. We help businesses and institutions prepare for a world where quantum computers will challenge today's security standards. Our clients include major financial institutions, defense actors, telecom operators, and global enterprises seeking to future-proof their cryptography., What's in it for you at CryptoNext * Join a deeptech company at the forefront of post-quantum cybersecurity. * Build the core data infrastructure of a cutting-edge observability platform. * Collaborate with world-class cryptographers and software engineers. * Flexible hybrid/remote policy and office in central Paris. * Competitive compensation aligned with seniority and expertise. * Direct impact on a product used by major financial and defense clients. * A chance to shape the future of quantum-safe data engineering.