Microsoft Sentinel Managed SIEM
We deploy and manage Microsoft Sentinel as your SIEM, connecting the log sources that matter, tuning detection rules against your environment, and keeping data ingestion costs under control rather than letting the bill surprise you.
A SIEM that ingests everything and detects nothing is a very expensive log store.
Sentinel gets sold as a straightforward proposition: connect your data sources, turn on Microsoft's built-in analytics rules, and threats get detected. The reality for most organisations is messier. Data ingestion is billed by volume, and connectors that look harmless — verbose firewall logs, Windows security event logs at full fidelity, a network device sending debug-level output — can turn a modest deployment into a bill nobody budgeted for within the first month.
The second problem is detection quality. Microsoft's out-of-the-box analytics rules are a reasonable starting point, but left untuned they generate incidents that don't reflect your actual environment — false positives from routine admin activity, missed detections because a rule assumes a data source you haven't connected. A fintech with FCA obligations and a manufacturer running an on-premise ERP need genuinely different rule sets, not the same defaults.
Visibility without response capacity is the third gap. An incident raised at 2am on a Saturday needs someone to look at it, decide whether it's genuine, and act, ideally within minutes rather than at 9am Monday. Organisations without a 24/7 function either accept that response window or need a managed service to cover it, and this decision needs making before deployment, not discovered afterwards.
Finally, Sentinel's usefulness depends on how well it's integrated with the rest of your security stack. If Defender, your firewall vendor's logs and your identity provider all feed in separately without a coherent correlation strategy, analysts end up manually stitching together a picture the platform should be building for them, which slows investigation exactly when speed matters most.
- Data ingestion costs spiralling from unscoped connectors
- Default analytics rules generating noise rather than genuine signal
- No 24/7 capacity to triage incidents outside office hours
- Log sources connected without a coherent correlation strategy
We scope the data first, then build detection around your environment.
Before connecting a single log source, we work out what actually needs to be in Sentinel and at what fidelity. High-value sources — identity, endpoint, email, critical servers — go in at full rate. Lower-value, high-volume sources go into cheaper basic or auxiliary log tiers, or get filtered before ingestion, so the cost profile matches the security value, not just the log volume available.
Detection rules are built and tuned against your specific environment, mapped against the MITRE ATT&CK framework so coverage gaps are visible rather than assumed. We start rules in a monitoring posture, review what they catch over a defined period, and adjust before anything moves into automated response, avoiding the alert fatigue that kills adoption of a new SIEM within the first quarter.
For organisations without 24/7 internal capacity, we provide managed SIEM services UK-wide — our analysts triage incidents around the clock, escalate genuine threats to you with context rather than raw alerts, and handle the routine noise so your team isn't woken at 2am for something that turns out to be a scheduled backup job.
Where you already run Microsoft Defender, we integrate its endpoint, email and identity signal directly into Sentinel so incidents correlate automatically rather than requiring an analyst to cross-reference two consoles. The same integration approach applies to firewalls, network devices and on-premise Active Directory where relevant.
- Data ingestion scoped and tiered before deployment, not after the first invoice
- Detection rules tuned against your environment and mapped to MITRE ATT&CK
- Managed SIEM monitoring available for 24/7 coverage without an in-house SOC
- Defender and network log sources correlated into a single incident view
Everything in the engagement, set out up front.
A managed SIEM engagement covering scoping, deployment, detection tuning and ongoing monitoring.
Data source scoping and cost modelling
A clear plan of what to ingest, at what tier, and a realistic monthly cost estimate before deployment starts.
Sentinel workspace deployment
Workspace configuration, retention policy and log tier setup aligned to your compliance and budget requirements.
Detection rule tuning
Analytics rules built and adjusted against your environment, mapped to MITRE ATT&CK for visible coverage.
Defender and third-party integration
Endpoint, email, identity and network log sources correlated into a single Sentinel incident view.
24/7 managed monitoring option
Round-the-clock incident triage and escalation for organisations without in-house SOC capacity.
Monthly cost and coverage review
Ongoing review of ingestion volume against budget, plus detection coverage against emerging threats.
What you receive.
- Data source scoping and ingestion cost model
- Sentinel workspace and retention configuration
- Tuned detection rule set mapped to MITRE ATT&CK
- Defender and network log source integration
- Incident escalation runbook with severity thresholds
- Managed monitoring service option with response SLAs
- Monthly ingestion and cost variance report
- Quarterly detection coverage review
Built for organisations that need the work done properly.
Organisations replacing a legacy SIEM
Businesses moving off an on-premise or appliance-based SIEM looking for lower cost and easier scaling.
Regulated firms needing genuine log visibility
A fintech with FCA obligations or an NHS supplier needing evidenced monitoring, not just a licence on paper.
Growing organisations without a SOC
Businesses that have outgrown ad-hoc log review but can't justify a 24/7 internal security team yet.
Microsoft-centric estates
Organisations already running Microsoft 365 and Defender who want their SIEM to correlate that signal natively.
What changes once the work is done.
What changes once Sentinel is properly scoped, tuned and monitored.
Predictable monthly cost
Data ingestion scoped and tiered against a budget agreed in advance, reviewed monthly rather than discovered on the invoice.
Detection that reflects your environment
Tuned rules mapped to MITRE ATT&CK catch relevant threats instead of generating noise from routine activity.
Round-the-clock response without an in-house SOC
Managed monitoring covers the hours your internal team can't, without the cost of building a 24/7 function.
One correlated view, not five consoles
Defender, network and identity signal brought together, so analysts spend time investigating rather than stitching data together.
Evidenced monitoring for audits
Documented detection coverage and incident handling supports regulatory audits, insurance renewal and client due diligence.
Faster genuine incident response
Well-tuned rules and clear escalation paths mean real threats are actioned in minutes, not discovered days later in a log review.
Why choose Secure Chain for managed Sentinel.
Deploying Sentinel is the easy part; most vendors can connect a data source and switch on a default rule. The work that actually reduces risk and controls cost is the scoping and tuning that happens before and after that initial connection, and that's where our experience running managed security services UK-wide across a range of Microsoft tenants makes the difference.
We treat cost control as a security requirement, not an afterthought. A Sentinel deployment that gets switched off or scaled back six months in because the bill wasn't managed properly leaves you with worse visibility than before you started. Our scoping work is designed to avoid that outcome from day one.
We support organisations across Chesterfield, Sheffield, Derby, Nottingham, Leeds, Manchester, Birmingham and London, either running Sentinel entirely on your behalf as a managed SIEM service or working alongside an internal team that owns day-to-day operations but wants our detection engineering and cost management expertise.
Where you're also running Microsoft Defender, Microsoft Security Copilot or considering Microsoft Purview for data governance, we design Sentinel's integration to bring all of that signal into one operational picture rather than treating each Microsoft security product as a separate project.
Questions we are asked most often.
What is Microsoft Sentinel?
Sentinel is Microsoft's cloud-native SIEM and SOAR platform, built on Azure. It ingests log data from your Microsoft 365 tenant, network devices, firewalls, identity providers and third-party tools, correlates it against detection rules, and raises incidents for investigation. We configure and manage it as your SIEM layer, either alongside our SOC or feeding into your own.
Isn't Sentinel expensive because it's billed on data volume?
It can be, if data sources are connected without thought. Sentinel bills primarily on the volume of log data ingested and retained, so a poorly scoped deployment connecting every verbose log source at full fidelity gets costly fast. Most of our early work is deciding what genuinely needs to be ingested at full rate, what can go to a cheaper basic tier, and what doesn't need collecting at all.
Do we need a SOC to run Sentinel, or can we manage it ourselves?
You can run it internally if you have the capacity to build detection rules, tune them over time and respond to incidents around the clock. Most organisations without a dedicated security team use a managed SIEM service instead, where we handle rule tuning, triage and escalation while you retain visibility over the incidents that matter.
How long does it take to get meaningful visibility?
Basic log ingestion from Microsoft 365 and Azure sources can be live within days. Meaningful detection coverage — tuned rules, connected on-premise and network sources, and an incident response process that actually works — typically takes four to eight weeks depending on how many data sources you're bringing in.
What's the difference between Sentinel and Microsoft Defender?
Defender covers endpoint, email, identity and cloud app protection directly. Sentinel is the SIEM layer that pulls Defender's signal together with everything else in your estate — firewalls, on-premise servers, third-party applications — into a single correlated view. Most Microsoft-centric organisations run both, with Defender feeding Sentinel.
Can Sentinel replace our existing SIEM?
Often, yes, and cost is usually the deciding factor — Sentinel's consumption-based pricing can be considerably cheaper than a traditional on-premise or appliance-based SIEM licence, particularly once data volumes are properly scoped. Migration needs planning so detection coverage doesn't gap during the switch.
How do you control the risk of unpredictable monthly costs?
We set data ingestion budgets per log source, use Sentinel's basic and auxiliary log tiers for high-volume, low-value data, apply retention policies matched to actual compliance need rather than default settings, and review consumption monthly so a misconfigured connector doesn't quietly triple your bill.
Microsoft Defender security services
Endpoint, email and identity protection tuned to feed directly into your Sentinel deployment.
Managed security services
24/7 monitoring and incident response backing your Sentinel SIEM deployment.
Case study: professional services MDR
How managed detection and response was deployed for a professional services client.
Want a realistic cost estimate before you commit to Sentinel?
Book a free scoping session and we'll model your likely ingestion cost and detection coverage before you spend anything.
Book a free scoping session