Job Description
Senior Probe Appliance Engineer - Cryptonext Security
Description
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
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Deploy, configure, and maintain the COMPASS probe appliance (hardware + Linux OS).
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Perform OS-level and kernel-level hardening (CIS benchmarks, secure boot, file integrity, access control).
Network Performance & Packet Capture
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Optimize the appliance for high-throughput packet capture using DPDK, AF_XDP, or zero-copy capture frameworks.
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Tune network interfaces, NIC offloading, IRQ distribution, and NUMA alignment.
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Build low-latency, high-performance data paths.
Data Ingestion & Pipeline Integration
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Guarantee secure, reliable ingestion into Kafka pipelines.
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Ensure compatibility and performance with downstream data and platform components.
Engineering Collaboration
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Work closely with R&D teams to integrate parsing modules, firmware updates, and kernel patches.
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Document operating procedures (installation, upgrades, troubleshooting).
Observability, Monitoring & Reliability
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Implement monitoring (metrics, logs, health checks).
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Maintain configuration management and full traceability of system changes.
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Run benchmarks, stress tests, and capacity planning.
Deployment Support
- Provide support to customers and integrators during field deployment (occasional on-site presence).
Security
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Contribute to the appliance’s security model:
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access control,
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secure boot chain,
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encryption (at rest and in transit),
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update pipeline security.
Requirements
The skills you'll need
Must-have
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10+ years of experience in system engineering, network engineering, or infrastructure security.
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Master’s degree from a French engineering school or equivalent.
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Deep expertise in:
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Linux system administration
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Kernel tuning and OS-level performance optimization
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Networking, packet capture, and traffic analysis
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Experience with:
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CIS, NIST, or ANSSI hardening methodologies
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Hardware optimization (CPU pinning, NUMA, NIC queues, hugepages)
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Kafka or streaming ingestion technologies
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Automation scripting (Bash, Python, Ansible)
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Excellent documentation skills and rigor.
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Fluent in English.
Bonus
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Experience with DPDK, AF_XDP, or similar high-throughput capture frameworks.
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Background in NDR / IDS / DPI appliances or packet inspection.
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Knowledge of secure boot chains, TPMs, or hardware-backed security.
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Experience with embedded Linux or containerized environments.
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Familiarity with Elasticsearch or observability stacks.
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Exposure to cryptographic or secure distributed systems.
The team you’ll be joining
You will join the COMPASS product engineering team, working closely with:
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R&D engineers building probe parsing logic and cryptographic modules
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Data engineering & platform teams managing ingestion and observability pipelines
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The Head of Engineering and CTO for architecture and long-term strategy
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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
- HR intro – get to know each other and understand your background.
- Technical interview with senior engineers + Head of Engineering (Linux, networking, OS tuning, probe performance).
- CTO meeting – architecture, deep-dive, and cultural fit.
- Offer & onboarding — welcome to CryptoNext!
Benefits
What’s in it for you at CryptoNext
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Shape a core component of a next-generation cybersecurity product.
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Work on challenging, low-level engineering problems involving kernel optimization and network performance.
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Collaborate with senior engineers and cryptography experts.
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Flexible hybrid/remote work with a central Paris office.
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Competitive compensation aligned with seniority.
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Direct impact on the technical backbone of a quantum-safe observability platform.
Company Info

CryptoNext Security
Develops Post-Quantum Cryptography (PQC) software solutions to manage the quantum threat and migrate...

