Custom SIEM & SOAR Development for MSSPs and Regulated Operators
Stop renting your security stack. Own it.
Per-GB licensing scales against you. Tenant isolation breaks down. Compliance exposure compounds. WhyCrew builds custom SIEM and SOAR platforms around your exact ingestion volume, tenancy model, and regulatory requirements, then hands the finished platform to your team, fully owned, zero vendor dependency.
- Zero-downtime migration from Splunk, Sentinel, or QRadar
- No per-GB licensing. No vendor lock-in. No recurring license cycle.
- Full platform ownership from day one
- Breakeven typically within 12–18 months
What you get
Full Deliverables, Every Engagement
Every engagement covers the same core scope. Nothing below is an upsell.
Security Data Lake Architecture
Custom schema on Elasticsearch or OpenSearch, designed around your real query patterns, not a vendor's generic model. Full-text search, fast aggregation, no per-GB licensing.
SIEM Ingestion Optimization
We rebuild your pipeline to filter noise at the source and tier retention by value, cutting 30–50% of raw ingestion volume in a single pass.
Custom Detection Logic
Correlation rules mapped to your actual threat model, fully documented and MITRE ATT&CK-aligned. No generic rulesets.
Custom SOAR Playbooks
Automation built around your real escalation paths: ticketing, chat, compliance reporting. Clients typically cut Tier-1 handling time by 70–80%.
Multi-Tenant Platform Design
For MSSPs: tenant isolation built in from day one, with separated data, RBAC, per-tenant retention, independent detection rules. Cost per new client drops as you scale.
Zero-Downtime Migration
Parallel-run validation from Splunk, Sentinel, QRadar, or any existing SIEM. No data loss. No visibility gaps. Detection parity validated before cutover.
Open Source Foundations
Built on Elasticsearch, OpenSearch, and Wazuh, with no licensing traps and full infrastructure control. For European clients, this delivers a cleaner NIS2 and DORA compliance story than any foreign-hosted SaaS.
Documentation & Training
Full API docs, deployment runbooks, and hands-on engineering training. Platform, infrastructure, and roadmap are yours from day one.
Build vs. buy
Is a Custom SIEM Worth It?
We run a full build vs. buy analysis before we recommend anything.
Build when
- Ingestion volume has outgrown per-GB pricing
- You need multi-tenant isolation a shared SaaS can't reliably provide
- Compliance obligations require data residency control your vendor can't meet
- Annual licensing could fund platform ownership within 12–18 months
Stay on subscription when
- Ingestion volume is low and likely to stay that way
- Your team has no capacity to operate a custom platform
- A SaaS platform already covers your compliance requirements
Not sure? Book a 20-minute Architecture Audit. We'll model your costs and give you a straight answer.
Splunk, Sentinel, and QRadar vs. Custom-Built SIEM
| Factor | Splunk | Microsoft Sentinel | IBM QRadar | Custom-Built (WhyCrew) |
|---|---|---|---|---|
| Pricing | Per-GB, rises with volume | Per-GB via Log Analytics | Per-event or capacity tier | One-time build, no ongoing fees |
| Ownership | Licensed access only | Microsoft-hosted with limited infrastructure control | IBM-hosted or on-prem with vendor dependency | Fully transferred: code, infrastructure, and roadmap |
| Flexibility | Proprietary SPL | KQL, Azure-coupled | Proprietary AQL | Open formats, no lock-in |
| Compliance | Splunk-constrained residency | Limited GDPR/NIS2 control | Vendor-dependent deployment model | Full control over location, retention, and logging |
| 3-Year Cost | +15–30% annually | Scales with consumption | Rises with license tiers | Flat after build |
Our process
How We Deliver Your Platform
Typical timeline: 12 weeks to full production. Zero downtime throughout.
- 01
Architecture Audit
We review ingestion volume, alert backlog, detection coverage, and compliance obligations. You receive a fixed-price proposal. No hourly billing. No scope creep.
- 02
Architecture Design
A full technical blueprint: data lake schema, detection logic framework, SOAR playbook design, and migration plan. You approve every component before we write a line.
- 03
Sprint-Based Build
Working software in your staging environment every two weeks. You test against real data and shape the next sprint. No black-box development.
- 04
Parallel Run & Validation
Your new platform runs alongside your legacy SIEM until detection parity is validated. If parity isn't reached, we don't cut over. We keep iterating at our cost.
Step 5. Handover & Ownership
Full API docs, runbooks, and hands-on engineering training. Your team takes complete control of the platform, infrastructure, and roadmap.
Investment & ROI
What This Costs, And What It Saves
| Cost Factor | Subscription SIEM | Custom-Built SIEM |
|---|---|---|
| Licensing | Scales with ingestion, increases yearly | One-time build, no per-GB fee |
| Lock-in | High, proprietary formats | None, full platform ownership |
| Scaling cost | Rises with data volume | Infrastructure cost only |
| Compliance control | Limited to vendor hosting | Full data residency control |
| 3-year trend | Up 15–30% annually | Flat after build |
Typical Investment Range
Single tenant, <500 GB/day
Multi-tenant MSSP, 500 GB–2 TB/day
Regulated operator, 2 TB+/day
Most clients reach breakeven within 12–18 months. Because you own the platform, savings compound every year as volume and client base grow. We can also package this as a multi-tenant, white-label SIEM deployment under your brand — see our MSSP Engineering Partner service for details.
Case studies
Client Results
NordSec GmbH, Hamburg, Germany
German MSSP · 40+ Enterprise Clients · Migrated from Splunk
40+ enterprise clients. €45,000/month Splunk bill. Detection logic locked in proprietary SPL. WhyCrew built a replacement Elasticsearch data lake, full SOAR playbook suite, and multi-tenant isolation in six weeks.
- 62% cost reduction
- €340K annual savings
- 0 hours downtime
- 6 weeks to production
UK Fintech, Regulated Under DORA
Migrated from Microsoft Sentinel
Sentinel consumption pricing was unpredictable and couldn't meet DORA data residency requirements. WhyCrew delivered an OpenSearch-based SIEM with full audit logging, SOAR integration with ServiceNow and Slack, and isolated tenants for payment processing and retail banking.
- 48% reduction in annual SIEM spend
- Full DORA compliance
- 8 weeks to handover
We needed to prove to our regulator that we controlled our entire security data lifecycle. WhyCrew delivered a platform we own, host, and audit ourselves.
Common concerns
Objections, Answered Directly
Hands-on training and full runbooks are included as standard. Most SOC engineers are productive within two weeks. Analysts adapt quickly to the new query workflows, and we provide translation guidance and hands-on training throughout the transition.
We map your existing detection logic 1:1 during migration, then train your team on the new query syntax. Nothing is lost in transition.
We design for supportability and document your exact version, configuration, and escalation paths before handover. Elasticsearch and OpenSearch both have robust commercial support options.
We architect for extensibility. If you need a capability the open core doesn't cover, we evaluate commercial plugins or custom development, always with full ownership of the result.
An optional post-handover retainer gives you direct access to the WhyCrew engineers who built your system. No ticket queues. No offshore L1.
Who we build for, by profile, region & fit
Who We Build For
Buyer Types
- MSSPs: High-volume, multi-tenant environments requiring strict client data isolation and scalable architecture
- Financial Services: DORA-regulated operators demanding full ICT risk control and audit-ready infrastructure
- Healthcare: GDPR-bound organizations that cannot compromise on data residency or patient data sovereignty
- Critical Infrastructure: Operators where data sovereignty and unbroken audit trails are non-negotiable
- SaaS & Cloud-Native Businesses: Scaling teams where per-GB licensing has become a structural cost problem
Regions Served
- Europe: Primary focus on NIS2, DORA, and GDPR environments where foreign-hosted SaaS creates compliance risk
- North America: MSSPs and regulated operators that require full infrastructure ownership and control
- Middle East & Asia-Pacific: Same engineering standard, deployed where you need it
Best Fit Environments
- Ingestion volume has outgrown per-GB pricing models
- Multi-tenant client isolation is a hard compliance or contractual requirement
- Data residency control cannot be delegated to a SaaS vendor
- Annual licensing spend could fund full platform ownership within 12–18 months
Frequently asked questions
Custom SIEM & SOAR, answered
We engineer a SIEM and SOAR platform around your operations, not a licensed product. You receive custom data lake architecture, ingestion pipelines, detection logic, and SOAR automation, with full documentation and hands-on training included.
Yes. We run your new platform in parallel until detection parity is validated, then cut over. We've completed zero-downtime migrations off all three platforms.
€60K–€250K for most builds, depending on tenant count, ingestion volume, and compliance complexity. Enterprise deployments may reach €400K. Fixed-price proposal delivered after the Architecture Audit, with no hourly billing and no scope creep.
Typically yes: Elasticsearch, OpenSearch, or Wazuh. No proprietary formats, no licensing traps.
Yes. Same engineering standard delivered to MSSPs and regulated operators worldwide. You choose where the infrastructure lives.
SOAR automates repetitive SOC tasks: alert enrichment, threat intelligence lookups, ticket creation, and containment actions. Our custom playbooks are built around your real escalation paths, typically cutting Tier-1 handling time by 70–80%.
Yes. Everything transfers to you at handover: infrastructure, roadmap, and all platform data. Nothing stays dependent on WhyCrew.
Most clients see a 40–70% reduction within the first 12 months, with breakeven typically reached within 12–18 months. Savings compound every year after.
Yes, with clean tenant isolation, per-client retention policies, and a white-label layer so your clients see your brand.
It depends on ingestion volume, engineering capacity, and compliance obligations. We give every prospective client an honest recommendation, including when the right answer is to stay with your current vendor.
An optional retainer covers upgrades, detection tuning, and engineering support, but the platform, infrastructure, and roadmap are yours from day one. No mandatory ongoing fees.
Stop renting your security stack. Own it.
Book a 20-minute Architecture Audit. We review ingestion volume, alert backlog, detection coverage, and compliance obligations, then deliver a fixed-price proposal.
Fixed-price proposal · No hourly billing · No scope creep