Senior Data & Platform Engineer

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

Résumé du poste

A deeptech startup in Paris is seeking a Senior Data & Platform Engineer to lead the design and operation of their data infrastructure. The ideal candidate has over 15 years of experience in software or data engineering, expertise in data modeling and PostgreSQL, and a commitment to code quality and reliability. This position offers a flexible hybrid/remote policy with competitive compensation.

Prestations

Flexible hybrid / remote policy

Competitive compensation

Direct impact on key products

Qualifications

• 15+ years of experience in software or data engineering in a distributed or complex environment.
• Deep expertise in data modeling & relational schema design.
• Strong hands-on experience with stream processing architectures.

Responsabilités

• Lead the design, setup, and operation of the entire data backbone powering COMPASS.
• Define and maintain the end-to-end data model for COMPASS.
• Design, validate, and maintain ingestion pipelines using Kafka.

Connaissances

Data modeling

PostgreSQL administration

Kafka

Elasticsearch

Stream processing architectures

ETL / ELT workflows

Data lifecycle management

Code quality

Documentation

Operational reliability

Fluency in English

Formation

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

Description du poste

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.

Requirements

The skills you'll need

Must-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!

Benefits

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.