Senior Probe Appliance Engineer

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.

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.

• 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).

• 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.

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

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

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

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

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

• 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.

• 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.

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.

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

• 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.