Topic : Modern SOC, XDR, SIEM, Detection & Response
Firm : AGCG Genuine Consulting Group
⏱ Reading time : ~10 minutes
Target audience : COMEX, CIOs, CISOs, SOC & SecOps managers
AGCG Watch Note – Decoding the reality behind the XDR vs SIEM debate and architecting a modern SOC.
Topic : Modern SOC, XDR, SIEM, Detection & Response
Firm : AGCG Genuine Consulting Group
In just a few years, the promise of XDR has deeply reconfigured the threat detection and response market. But behind the slogans like "Next-Gen SOC", "Extended Detection", or "Native XDR", the central question remains: how to rationally integrate XDR and SIEM?
For organizations, the challenge is not about choosing one or the other, but architecting a model that maximizes visibility, detection, and governance, without unnecessarily increasing costs.
Since 2022, the narrative from cybersecurity vendors has shifted. While SIEM traditionally held the central role in security event detection, major market players are now promoting XDR (Extended Detection & Response) platforms, presented as simpler, more integrated, and more effective.
The pitch is appealing: less complexity, less noise, more correlation, and automated response. But behind this marketing positioning, the reality of organizations is more nuanced. Does XDR really replace SIEM, or does it just change its role?
For AGCG, the question is not "XDR or SIEM," but "how to intelligently combine both in a modern SOC architecture?"
SIEM remains the cornerstone of security event centralization:
Strengths: universality, scalability, ability to cover the entire IT environment, and compliance requirements. Weaknesses: high noise volume, storage costs, complex tuning, expertise shortage.
XDR natively unifies several sources of telemetry: endpoint (EDR), network (NDR), identity, email, sometimes cloud and SaaS. It is designed to operate within a well-defined perimeter, with strong integration between components.
Strengths: native correlation, behavioral detection, enhanced analyst experience, automated response within its perimeter. Weaknesses: strong vendor dependency, limited coverage outside the ecosystem, difficulty handling purely compliance or audit use cases.
Studies from firms like Gartner and Forrester show that SIEM remains indispensable in large organizations, but its role is evolving towards becoming a security data lake:
For mid-sized companies, XDR appears as a pragmatic compromise: it offers significant coverage, simpler deployment, and lower operational cost compared to traditional SIEM, while improving detection through native correlation between endpoint, identity, email, etc.
In complex organizations (multi-cloud, multi-country, multi-SOC), the emerging model is that of a structured coexistence:
In this model, XDR detects quickly and effectively within its perimeter, and SIEM consolidates, retains, and links XDR signals to other events in the IT ecosystem.
In complex environments, this statement is rarely true. XDR does not cover all the use cases for compliance, nor all types of necessary logs (business systems, OT, legacy equipment, etc.). SIEM remains necessary to aggregate and retain a global view.
XDR reduces noise within its perimeter thanks to native correlation and shared context. But it does not eliminate the need for fine-tuning, nor the need to govern use cases. Noise is moved and transformed, not magically eliminated.
XDR typically correlates better than SIEM for signals within its own ecosystem (endpoint, network, identity, email). But when it comes to cross-referencing multiple events (business systems, OT, legacy systems, specific application logs), SIEM becomes the only platform capable of aggregating all the data.
For mid-sized organizations, a well-chosen XDR can cover much of the detection-response needs without a dedicated SIEM, especially when :
In this model, XDR is the operational detection-response layer, while SIEM ensures consolidation, compliance, and the broader global view. Typical data flows:
Some "next-gen" SIEMs are integrating traditionally XDR features: UEBA, advanced analytics, SOAR, native connectors, prebuilt detection packs. The market is thus moving towards functional convergence rather than direct opposition.
To move beyond the theoretical debate, AGCG offers a decision-making framework along four axes :
Based on these parameters, the right question is not "XDR or SIEM," but : "Which role should each component play in a coherent architecture?"
“The XDR vs SIEM debate is a false issue: in a modern SOC, the challenge is not about choosing a side, but designing an architecture where each component plays its role in a controlled detection-response value chain.”
— AGCG Genuine Consulting Group
The "XDR vs SIEM" debate fills much of the marketing space, but it poorly reflects the reality of organizations. In practice, XDR and SIEM are converging into an architecture where :
For executives, the challenge is to move away from a technological stacking logic and build a SOC trajectory : define the place of each component, clarify responsibilities, measure performance (MTTD, MTTR, detection coverage, noise reduction) and link it all to a business risk vision.
At AGCG, we help organizations transform this debate into structuring decisions : platform choice, target architecture, SOC roadmap, service contracts, risk-based management. Beyond the acronyms, we return to the essentials : detect faster, respond better, and give visibility to the COMEX.