Who we are

CryptoNext Security is a deeptech startup specializing in post-quantum cryptography. We help businesses and institutions get ready for a world where quantum computers will break today’s cryptography.
Our customers include major banks, defense actors, telecom operators, and large enterprises securing their most sensitive infrastructures.

On a daily basis, you will

As Senior Probe Appliance Engineer, you will take full technical ownership of the COMPASS probe appliance, a high-performance hardware + software component responsible for packet capture, telemetry extraction, and encrypted traffic analysis.

You will work across the full lifecycle of the appliance: system installation, kernel-level tuning, security hardening, performance optimization, reliability engineering, and operational excellence.

System, OS & Installation

• Deploy, configure, and maintain the COMPASS probe appliance (hardware + Linux OS).
• Perform OS-level and kernel-level hardening (CIS benchmarks, secure boot, file integrity, access control).

Network Performance & Packet Capture

• Optimize the appliance for high-throughput packet capture using DPDK, AF_XDP, or zero-copy capture frameworks.
• Tune network interfaces, NIC offloading, IRQ distribution, and NUMA alignment.
• Build low-latency, high-performance data paths.

Data Ingestion & Pipeline Integration

• Guarantee secure, reliable ingestion into Kafka pipelines.
• Ensure compatibility and performance with downstream data and platform components.

Engineering Collaboration

• Work closely with R&D teams to integrate parsing modules, firmware updates, and kernel patches.
• Document operating procedures (installation, upgrades, troubleshooting).

Observability, Monitoring & Reliability

• Implement monitoring (metrics, logs, health checks).
• Maintain configuration management and full traceability of system changes.
• Run benchmarks, stress tests, and capacity planning.

Deployment Support

• Provide support to customers and integrators during field deployment (occasional on-site presence).

Security

• Contribute to the appliance’s security model:
• access control,
• secure boot chain,
• encryption (at rest and in transit),
• update pipeline security.

The skills you'll need

Must-have

• 10+ years of experience in system engineering, network engineering, or infrastructure security.
• Master’s degree from a French engineering school or equivalent.
• Deep expertise in:
• Linux system administration
• Kernel tuning and OS-level performance optimization
• Networking, packet capture, and traffic analysis
• Experience with:
• CIS, NIST, or ANSSI hardening methodologies
• Hardware optimization (CPU pinning, NUMA, NIC queues, hugepages)
• Kafka or streaming ingestion technologies
• Automation scripting (Bash, Python, Ansible)
• Excellent documentation skills and rigor.
• Fluent in English.

Bonus

• Experience with DPDK, AF_XDP, or similar high-throughput capture frameworks.
• Background in NDR / IDS / DPI appliances or packet inspection.
• Knowledge of secure boot chains, TPMs, or hardware-backed security.
• Experience with embedded Linux or containerized environments.
• Familiarity with Elasticsearch or observability stacks.
• Exposure to cryptographic or secure distributed systems.

The team you’ll be joining

You will join the COMPASS product engineering team, working closely with:

• R&D engineers building probe parsing logic and cryptographic modules
• Data engineering & platform teams managing ingestion and observability pipelines
• The Head of Engineering and CTO for architecture and long-term strategy
• Product and QA teams to ensure reliability, performance, and compliance

You will be the reference engineer for everything related to probe performance, appliance security, and kernel-level tuning.

Our recruitment process

1. HR intro – get to know each other and understand your background.
2. Technical interview with senior engineers + Head of Engineering (Linux, networking, OS tuning, probe performance).
3. CTO meeting – architecture, deep-dive, and cultural fit.
4. Offer & onboarding — welcome to CryptoNext!

What’s in it for you at CryptoNext

• Shape a core component of a next-generation cybersecurity product.
• Work on challenging, low-level engineering problems involving kernel optimization and network performance.
• Collaborate with senior engineers and cryptography experts.
• Flexible hybrid/remote work with a central Paris office.
• Competitive compensation aligned with seniority.
• Direct impact on the technical backbone of a quantum-safe observability platform.