Success Story

Transforming SIEM Economics and Visibility with Microsoft Sentinel

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Industry: Professional Services & Engineering
Microsoft Technology: Microsoft Sentinel, Microsoft Defender XDR, Microsoft Sentinel Data Lake
Ascent Solution: Sentinel Rapid Adoption + SIEM Migration

Ascent partnered with a professional services and engineering firm to dramatically reduce SIEM costs while improving security visibility through a strategic migration from Splunk to Microsoft Sentinel. The engagement delivered significant cost savings, enhanced detection capabilities, and a modern, scalable SIEM architecture.

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Results at a Glance:

Reduced Ingestion

SIEM ingestion reduced from 6 TB/day to 2.5 TB/day

Major Cost Savings

Significant savings through Sentinel Data Lake & E5 ingestion benefits

Enhanced Detection

Improved visibility across high-volume network environments

Modern Architecture

Scalable SIEM foundation with successful Splunk displacement

The Challenge

Ballooning SIEM Costs and Limited Visibility

Our client is a large, globally distributed organization responsible for managing massive volumes of telemetry and network traffic across thousands of endpoints and edge locations. Their legacy SIEM environment, built on Splunk, ingested over 6 TB of logs per day, driven heavily by noisy firewall data and manual ingestion pipelines.

This created several critical challenges: escalating SIEM licensing and storage costs, inefficient ingestion pipelines especially for Fortinet traffic, difficulty scaling visibility without skyrocketing spend, and underutilization of Microsoft E5 Security entitlements.

Maintaining the Splunk environment became financially unsustainable, even as visibility gaps persisted. They needed a modern SIEM approach—one designed for scale, automation, and cost efficiency.

The Solution

Migrating to Sentinel + Data Lake for Exponential Savings

Ascent Solutions led a strategic migration from Splunk to Microsoft Sentinel, leveraging Sentinel's new Data Lake–centric architecture to completely rethink SIEM cost, retention, and insight. Ascent delivered a modern SIEM ingestion strategy built for scale.

Key Focus Areas

  • Shifted high-volume syslog and firewall traffic into Sentinel Data Lake, drastically reducing ingestion cost.
  • Re-architected ingestion pipelines to eliminate manual log configuration.
  • Reduced daily ingestion from 6 TB to 2.5 TB through intelligent data tiering.
  • Optimized Microsoft E5 ingestion benefits (5 MB/user/day) to unlock additional cost savings.
  • Designed a repeatable, scalable ingestion architecture for long-term SOC modernization.
Microsoft Sentinel Rapid Adoption Offer

The Impact

More Visibility, Lower Cost, Stronger Security Posture

The migration to Microsoft Sentinel delivered measurable improvements immediately. By redesigning the client's ingestion architecture and shifting high-volume firewall logs into Sentinel's Data Lake, Ascent helped the organization unlock a level of cost efficiency, performance, and visibility that was not possible in their Splunk environment.

Key Outcomes

  • Major Cost Reduction: By moving to Sentinel's Data Lake model, we were able to significantly reduced ingestion cost while increasing retention flexibility and analytical depth.
  • Improved Detection and Visibility: With Sentinel and Defender XDR working together, the client now detects more alerts and more potential threats than before, without adding more tooling.
  • Smarter Use of Existing Investments: As an E5-licensed organization, the client finally realized the financial and operational benefits of leveraging the Microsoft Security stack they were already paying for.
  • Scalable SIEM Architecture: The migration created a foundation that is easier to maintain, easier to extend, and ready for evolving security and data requirements.
  • Repeatable Pattern for SIEM Displacement: This success demonstrates that enterprises can move away from high-cost SIEMs like Splunk without losing visibility or maturity—in fact, the client gained both.

Leadership highlighted Sentinel's ability to expand visibility, eliminate unnecessary tooling, and dramatically reduce SIEM spend, all while improving operational efficiency.

The Future

Continued SOC Modernization

Ascent continues to support the client's security journey, providing guidance on additional data sources, analytics optimization, automation opportunities, and future SOC modernization efforts.

Our goal is to turn security modernization into a catalyst for operational efficiency and long-term risk reduction, building a sustainable, high-performing security operations foundation that evolves with your organization.

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Why Choose Ascent

The client chose to partner with Ascent because of our proven ability to execute large-scale Microsoft Sentinel migrations with speed, precision, and measurable business impact. As a Microsoft-focused security consultancy, Ascent brings deep technical expertise, extensive field experience, and a repeatable framework for transforming SIEM operations.

Large-Scale SIEM Displacement

Proven methodology for migrating from legacy SIEM platforms to Microsoft Sentinel

Data Lake Expertise

Deep knowledge of Sentinel Data Lake design and ingestion optimization strategies

E5 Optimization

Expertise in maximizing value from Microsoft E5 Security investments

By combining technical execution with strategic planning, Ascent helped them transform their security operations while dramatically reducing costs.

Ready to modernize your SIEM? Explore Ascent's Sentinel Rapid Adoption Offer and see how we can help reduce SIEM cost, improve detection, and unlock the full power of Microsoft Security.

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