Senior Security Operations Engineer

DiliTrust; Rueil-Malmaison; On-site; EUR 70,000 - 95,000; Full time

Job summary

DiliTrust is seeking a Security Operations Engineer to protect its SaaS platform, cloud infrastructure, networks and production environments. You will join a 12‑person Infrastructure & Security team scattered across France, Canada and Spain, working in an international context.

You will monitor, respond to incidents, manage vulnerabilities, harden systems and automate using IaC, collaborating with DevOps, development and product teams to embed security in architecture and delivery.

Qualifications

• 5+ years in Security Operations, Cybersecurity, Infrastructure Security, Cloud Security or related field.
• Experience with security monitoring, incident response, vulnerability management, system hardening and operational security.

Responsibilities

• Monitor security of networks, cloud infrastructure, systems, applications and endpoints.
• Administer, configure and improve CNAPP, SIEM, EDR, bastion, ZTNA, PKI, antivirus and WAF solutions.
• Evolve detection mechanisms and threat-detection scenarios.
• Investigate security alerts and incidents; support root-cause analysis and remediation.
• Automate deployments and security/infra operations using IaC and scripting.
• Create and maintain security procedures, incident-response playbooks and standards.
• Define and deliver the security roadmap with Hiring Manager and peers.
• Stay updated on threats and share learnings with the team.

Skills

Linux basics

Docker

Kubernetes

Networking

Infrastructure as Code

Terraform

Ansible

AWX

PKI

WAF

Monitoring tools

Scripting

Tools

Prometheus

Grafana

Datadog

Job description

As a Security Operations Engineer, you will help protect DiliTrust’s SaaS platform, cloud infrastructure, networks and production environments. You will join the Infrastructure & Security team, a 12-person team spread across France, Canada and Spain, and work in an international context (Europe, North America and EMA). The infrastructure you will secure is managed in an automated way and counts more than 350 assets hosted across our cloud providers.

You will contribute to the continuous improvement of our security posture through monitoring, incident response, vulnerability management, hardening and automation, and you will work closely with infrastructure, DevOps, development and product teams so that security is embedded into our architectures, operations and delivery processes.

Missions:

In this role, your main responsibilities will include:

Security monitoring & incident response

• Monitor the security of networks, cloud infrastructure, systems, applications and endpoints.
• Administer, configure and continuously improve our security tools, including CNAPP, SIEM, EDR, bastion, ZTNA, PKI, antivirus and WAF solutions.
• Continuously evolve our detection mechanisms and threat‑detection scenarios.
• Investigate security alerts and incidents, support incident handling, and contribute to root‑cause analysis, remediation and post‑incident reviews.

Hardening, vulnerabilities & secure architecture

• Implement hardening measures and support vulnerability identification, prioritization, remediation and follow‑up through action plans.
• Validate the security aspects of IT architectures and application projects.
• Actively participate in security audits and penetration tests: scoping, support during the exercise, remediation of findings and follow‑up.
• Test products and run technical validations on prototype environments before they reach production.

Automation & Infrastructure as Code

• Automate deployments and security / infrastructure operations using Infrastructure as Code, configuration management and scripting.
• Create and maintain security procedures, incident‑response playbooks, operational documentation and technical standards.

Roadmap, watch & knowledge sharing

• Define and deliver the team’s security roadmap together with the Hiring Manager and your peers.
• Keep an active watch on threats and security news, and share what you learn with the team.

Candidate Profile:

Experience & seniority

• You have at least 5 years of professional experience in Security Operations, Cybersecurity, Infrastructure Security, Cloud Security or a related field (network, systems or cloud engineering with a strong security component).
• You have practical experience with security monitoring, incident response, vulnerability management, system hardening and operational security.

Mindset & collaboration

• You are passionate about cybersecurity and interested in automation and the DevOps culture; you would rather automate a process than repeat it.
• You are analytical, autonomous, versatile and rigorous, with a strong sense of service and good synthesis skills.
• You communicate clearly with both technical and non‑technical stakeholders, and you are confident in your expertise without losing the team spirit.
• You enjoy working collaboratively in an international, distributed team and have a good command of English.

Technical Skills:

Required

• Good knowledge of Linux (Debian-based environments in particular), Docker and Kubernetes;.
• Good knowledge of networking, enough to design, routing and firewall rules: TCP/IP, DNS and TLS; static routing, VLANs, segmentation and NAT; stateful and application‑level firewall rule design; reverse proxies and load balancers; VPN and overlay technologies (WireGuard, IPsec); ZTNA principles (identity‑aware access, device posture, micro‑segmentation); cloud networking (VPC, peering, private endpoints).
• Ability to manage network and security configurations as code, using Infrastructure as Code and automation tools such as Terraform, Ansible and AWX.
• Good knowledge of PKI and certificate management: CA hierarchies, certificate lifecycle (issuance, renewal, revocation, automation), TLS / mTLS, key and secret management.
• Administration of security tools: CNAPP, SIEM, EDR, bastion, ZTNA and PKI, including interpreting security events and alerts.
• Hands‑on experience with WAF (policy and rule tuning).
• Familiarity with monitoring tools such as Prometheus, Grafana and Datadog.
• Ability to script and automate repetitive operational or security tasks.

Nice to have

• Knowledge of Google Cloud Platform or an equivalent cloud environment.
• An active interest in security news, emerging threats, conferences and meetups.

Our Security & Infrastructure Environment:

• Cloud: Google Cloud Platform and other cloud providers, with automated infrastructure management (700+ assets)
• Systems & containers: Linux (Debian), Docker, Kubernetes
• Automation: Ansible, AWX, Terraform
• Network & access: ZTNA, bastion
• Security tooling: SIEM, EDR, WAF, antivirus, PKI
• Monitoring: Prometheus, Grafana, Datadog

Process:

• Interview with a member of the Talent Acquisition team (30–45 minutes)
• Technical interview with the SecOps Team Lead and the Team manager, including a practical case study (about 90 minutes)
• Final interview with the CTO (60 minutes)