Aug 18, 2025

René Herzer
"Where should I run my AI systems?" This question confronts CIOs daily. The answer seems simple: cloud is modern, scalable, and cost-effective. However, AI as the fourth layer of IT architecture brings new requirements that turn traditional hosting decisions upside down.
Why AI Hosting is Different
With traditional software, the hosting decision is usually a matter of cost: cloud for flexibility, on-premises for control. With AI systems, new dimensions are added:
Data residency becomes critical: AI models require continuous access to training data. Where this data may be stored often determines the hosting option.
Compliance becomes complex: An AI system that makes decisions about credit approval or medical diagnoses is subject to different regulatory requirements than a CRM system.
Performance is unpredictable: AI workloads can spontaneously increase tenfold when complex queries are made. Traditional capacity planning fails.
The Three Hosting Options in Detail
Cloud AI: Fast, but with caveats
Advantages:
Instant access to GPU capacity
Managed services for ML pipelines
Automatic scaling
No hardware investments
Disadvantages:
Data leaves the company
Vendor lock-in with specialized services
Unpredictable costs with intensive usage
Latency with large data volumes
Suitable for: Startups, non-critical applications, prototyping
On-Premises: Control at Any Cost
Advantages:
Complete data control
Compliance security
Predictable costs
No dependency on internet connections
Disadvantages:
High initial investments
Complex hardware management
Limited scalability
Expertise development required
Suitable for: Banks, healthcare, government agencies, companies with sensitive data
Hybrid: The Best of Both Worlds?
Advantages:
Sensitive data remains internal
Cloud for peak loads
Gradual migration possible
Flexibility for different applications
Disadvantages:
Complex Architecture
Data Flow Management Required
Dual Expertise Necessary
Potential Security Vulnerabilities at Interfaces
Suitable for: Large companies with mixed requirements
The Decision Matrix
Regulatory Requirements
Health data (GDPR Art. 9): On-premises or certified EU cloud
Financial data (MaRisk, Solvency II): On-premises with documented exceptions
Personnel data: Hybrid possible, but with strict separation
Trade secrets: Dependent on company policy
Technical Requirements
Real-time decisions: On-premises for minimal latency
Batch processing: Cloud for cost efficiency
Continuous learning: Hybrid for flexibility
Experimental projects: Cloud for rapid iteration
Organizational Factors
Existing expertise: Cloud when lacking AI know-how
Investment budget: Cloud for low initial costs
Long-term strategy: On-premises for strategic AI systems
Vendor preferences: Dependent on existing partnerships
Practical Decision-Making Aids
Questions you should ask yourself
Data classification: Which of your data may leave the company?
Compliance requirements: Which auditors do you need to satisfy?
Performance requirements: How critical are response times?
Scaling expectations: How much will AI usage grow?
Expertise availability: Do you have AI operations know-how?
Typical Scenarios
Scenario 1: Medium-sized Bank
Requirement: Credit risk assessment
Decision: On-premises
Reason: BaFin compliance, sensitive financial data
Scenario 2: E-Commerce Company
Requirement: Product recommendations
Decision: Cloud
Reason: Scalability, non-critical data
Scenario 3: Pharmaceutical Corporation
Requirement: Research Data Analysis
Decision: Hybrid
Reason: Sensitive research data internal, computing power from cloud
The Hidden Costs
Cloud-Fallen
Data egress fees: Transferring large datasets can become expensive
Specialized services: GPU instances quickly cost five-figure amounts monthly
Vendor lock-in: Migration between cloud providers is complex and expensive
On-Premises Realities
Hardware refresh: GPU technology evolves rapidly
Expertise costs: AI operations specialists are expensive and scarce
Underutilization: Hardware often sits unused
Hybrid complexity
Dual infrastructure: Costs for both environments
Integration: APIs and data flows between environments
Security: Protection of hybrid interfaces
What really works
Start with clear data classification
Before you decide on hosting, categorize your data:
Public: Cloud without restrictions
Internal: Cloud with encryption
Confidential: Hybrid with strict separation
Secret: On-premises only
Start with pilot projects
Cloud-First for Experiments: Test new AI applications in the cloud first
On-Premises for Production: Operate proven systems internally
Hybrid for Scaling: Offload peak loads to the cloud
Plan exit strategies
Avoid vendor lock-in: Use standardized APIs and data formats
Prepare for migration: Documentation and processes for transitions
Multi-cloud strategy: Reduce dependencies on individual providers
The strategic dimension
AI hosting is not just a technical, but a strategic decision. It determines:
Which AI applications you can actually implement
How quickly you can respond to new requirements
How dependent you become on external providers
Today's hosting decision shapes your AI strategy for years to come. Don't just choose for today, but for the AI-native organization you want to become.
The question isn't "Cloud or on-premises?" but rather "Which hosting strategy enables our AI vision?" The answer to that is individual – but it should be made deliberately.
This is the fourth part of our series on AI integration beyond pilot projects. Next week: Which AI governance policies you really need and what must be included in them.
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