Cybersecurity: protect, strengthen and govern your IS
Rising threats, expanded attack surfaces, growing regulatory requirements: cybersecurity is a strategic challenge for all organizations. Castelis supports you across the entire cyber spectrum, from governance and compliance to operational monitoring and technical hardening of your IS.
ISO 27001:2022 Certified
CyberVadis 2025 Platinum
Integrated approach
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A comprehensive and certified cyber approach
From architecture audits to penetration tests, from 24/7 SOC monitoring to ISO 27001 governance, Castelis covers the full cybersecurity spectrum. Holders of the CyberVadis 2025 Platinum medal (983/1000) and ISO 27001:2022 certified, our teams commit to the best market practices.
Whether you need to structure your governance, strengthen your technical defenses, or operate a SOC, we work in project mode or continuous operational mode, with specialized experts and proven processes.
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IS Architecture Audits, Penetration Testing & Security Hardening
Evaluate the robustness of your systems with architecture, configuration and code audits. Our experts conduct real-world penetration tests and Purple Team exercises to identify vulnerabilities, test your defenses, and deploy targeted protections on your workstations, servers, networks, and applications.
- Architecture & configuration audits
- Penetration testing (pentest)
- Purple Team exercises
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Managed SOC: 24/7 detection and response
An operational SOC that continuously monitors your IS, qualifies alerts, and responds to incidents in real time. Dedicated analysts, log correlation, threat hunting and Cyber Threat Intelligence: our SOC combines human expertise and advanced tools for a proactive defense of your information system.
- 24/7 monitoring & detection
- Threat Hunting & CTI
- Structured incident response
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Governance, Risk & Compliance (GRC)
Structure and manage your cybersecurity with a comprehensive GRC approach. ISO 27001 certification, GDPR compliance, ISMS deployment, security policies, BCP/DRP, and crisis exercises: we support you from initial audit to continuous improvement of your governance.
- ISO 27001 & GDPR
- ISMS & security policies
- BCP/DRP & crisis management
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Cybersecurity experts on-demand
Strengthen your internal teams with experienced cybersecurity profiles: CISOs, SOC engineers, analysts, pentesters, DevSecOps experts. Our consultants integrate into your tools and processes for targeted or long-term assignments, with continuous monitoring by Castelis.
- CISOs & security engineers
- SOC analysts & pentesters
- DevSecOps experts
/ An ecosystem of recognized partners
We work with leading cybersecurity publishers and partners to deploy recognized solutions and maintain a level of expertise at the forefront of current threats.
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FAQ
An approach based on your maturity and priorities
It all depends on your cyber maturity level. If you don’t yet have a formalized security policy, GRC is often the right starting point. If you have exposed systems without a recent test, a technical audit is the priority. If you lack visibility into incidents, the SOC is essential.
We can help you establish a diagnosis of your cyber posture and prioritize actions to take based on your constraints and regulatory context.
Governance and technical: two inseparable pillars
Technical security (audits, pentests, deployment of protections) addresses the operational dimension and immediate risks. GRC structures the cyber approach over time: policies, responsibilities, regulatory compliance, and resilience. One without the other leaves blind spots.
Our most mature clients combine both approaches for a coherent and sustainable cyber posture.
External recognition on the most demanding standards
Castelis is ISO 27001:2022 certified and holds the CyberVadis 2025 Platinum medal with a score of 983/1000. These distinctions attest to a high level of maturity in governance, operational processes, and technical mechanisms.
For our clients, it is the assurance of working with a partner aligned with the best market practices and committed to continuous improvement.
Modular support according to your needs
Yes. Our clients frequently combine multiple expertises based on their challenges: GRC in parallel with a technical audit, SOC reinforced by an expert staffing team, or comprehensive support covering the full cyber spectrum.
We offer a solution tailored to your organization, adjustable over time as your priorities and risks evolve.
Let's talk about your cyber strategy
