Senior Data & Platform Engineer

Limelight Health; Paris; Hybride; EUR 85 000 - 120 000; Plein temps

Résumé du poste

A cybersecurity startup in Paris seeks a Senior Data & Platform Engineer to lead the design and operation of their data backbone for a cutting-edge observability platform. The ideal candidate has over 15 years of experience in data engineering, master’s degree, and expertise in PostgreSQL, Kafka, and Elasticsearch. This role offers a flexible hybrid work model and competitive compensation.

Prestations

Flexible hybrid/remote policy

Competitive compensation

Direct impact on major projects

Qualifications

• 15+ years of experience in software or data engineering in a distributed environment.
• Strong commitment to code quality, documentation, and operational reliability.

Responsabilités

• Lead the design, setup, and operation of the data backbone for 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 / ELK stack

Stream processing architectures

ETL/ELT workflows

Fluency in English

Formation

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

Outils

Kafka

PostgreSQL

Elasticsearch

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.

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

1. HR Intro – a first conversation to understand your background and expectations.
2. Technical Interview with a senior engineer and the Head of Engineering (Kafka, PostgreSQL, ELK, data modeling).
3. CTO Meeting – deep dive on architecture, COMPASS roadmap, and cultural fit.
4. 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.