Senior Data & Platform Engineer

Who we are 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. On a daily basis, you will As Senior Data & Platform Engineer, you will lead the design, setup, and operation of the entire data backbone powering COMPASS, our observability and orchestration platform for post-quantum cryptography deployments.

Your missions include:

Data Modeling & Governance

• 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.
• Ingestion, Streaming & Storage
• 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. Observability & Data Quality Contribute to platform-wide observability by defining structured logs, metadata standards, and ingestion patterns. Promote best practices for data quality, versioning, retention, and schema evolution. The skills you'll needMust-have 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. Bonus

• 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. The team you’ll be joining

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.
• Our recruitment process
• HR Intro – a first conversation to understand your background and expectations.
• 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!

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.