How Companies Are Choosing Their AI Strategy
Organizations face a critical choice: adopt managed AI services like ChatGPT Enterprise and Microsoft 365 Copilot for speed and simplicity, or build custom stacks using open models, vector databases, and RAG for control and cost efficiency at scale. Hybrid approaches increasingly prevail as companies optimize different use cases differently.
12/28/20234 min read


Every enterprise technology leader now faces a fundamental question: should we buy managed AI services or build our own? The choice between adopting ChatGPT Enterprise, Microsoft 365 Copilot, or similar offerings versus constructing custom AI stacks using open models, vector databases, and retrieval-augmented generation (RAG) architectures represents one of the most consequential technology decisions of the decade. Neither answer is universally correct—the right choice depends on resources, requirements, and risk tolerance in ways that mirror classic build-versus-buy dynamics, but with novel complications.
The Managed Service Appeal
ChatGPT Enterprise, Microsoft 365 Copilot, and Google Duet AI offer compelling simplicity: sign contracts, provision users, and deploy AI capabilities across the organization within days rather than months. The value proposition is straightforward.
Speed to deployment represents the most obvious advantage. Organizations can have employees using sophisticated AI tools almost immediately, without recruiting specialized AI talent, building infrastructure, or navigating complex technical implementation. For companies where time-to-value matters more than customization, this speed is decisive.
Minimal technical overhead appeals to organizations with limited AI expertise. Managed services handle model updates, infrastructure scaling, security patching, and operational maintenance. IT teams already stretched thin appreciate not adding AI operations to their responsibilities.
Integration advantages matter significantly for Microsoft and Google offerings. If your organization already lives in Microsoft 365 or Google Workspace, Copilot and Duet integrate seamlessly into familiar tools. The AI appears in Outlook, Word, Teams—where employees already work—rather than requiring new interfaces and workflows.
Enterprise-grade security and compliance come built-in. These services offer SOC 2 compliance, data processing agreements, and contractual guarantees about data handling that give legal and compliance teams confidence. For regulated industries, these checkboxes often prove non-negotiable.
Predictable costs make budgeting straightforward. ChatGPT Enterprise at $60/user/month or Microsoft 365 Copilot at $30/user/month provide clear per-seat pricing. Finance teams appreciate predictability over the variable costs and hidden complexity of self-built solutions.
The DIY Case
Yet many organizations—particularly those with technical sophistication, unique requirements, or high usage volumes—find compelling reasons to build rather than buy.
Cost advantages at scale favor custom solutions dramatically. Organizations processing millions of AI requests monthly might spend hundreds of thousands on API services but only tens of thousands on infrastructure for self-hosted models. The economics flip decisively at sufficient volume.
Companies like Bloomberg have publicly discussed running their own fine-tuned models at a fraction of what comparable API usage would cost. For high-volume use cases, the development investment pays back quickly.
Data sovereignty and control drive many organizations toward self-hosted solutions. Financial institutions, healthcare providers, and government agencies often cannot send sensitive data to external APIs, regardless of contractual protections. Running models entirely within their security perimeter satisfies requirements that managed services cannot.
Customization and fine-tuning enable capabilities impossible with generic services. Organizations can fine-tune open models on proprietary data—internal documentation, domain-specific language, company terminology—creating assistants that understand their unique context in ways general-purpose models never will.
Legal firms are training models on case law and precedents. Healthcare organizations are fine-tuning on medical literature and clinical guidelines. Manufacturing companies are adapting models to technical specifications and industry jargon. This specialization delivers competitive advantages managed services cannot provide.
Multi-modal and experimental architectures become feasible. Organizations can combine multiple models—using smaller, faster models for simple tasks and larger models for complex reasoning. They can implement sophisticated RAG architectures with custom retrieval strategies, integrate proprietary databases seamlessly, and experiment with cutting-edge techniques as they emerge.
Vendor independence protects against lock-in and price changes. Organizations building on open models aren't hostage to single-vendor pricing or terms-of-service changes. If Llama 2 becomes unsuitable, they can switch to Mistral, Falcon, or whatever emerges next, without rearchitecting entirely.
The Hybrid Middle Ground
Increasingly, sophisticated organizations aren't choosing between managed and DIY—they're doing both.
Hybrid architectures use managed services for some workflows and custom solutions for others. General employee productivity might run on ChatGPT Enterprise while specialized applications use fine-tuned models. Customer-facing chatbots might use self-hosted models for data control while internal tools use managed services for convenience.
This approach optimizes for different priorities across use cases: speed and ease for general use, cost and customization for specialized applications.
Progressive sophistication represents another common pattern. Organizations start with managed services to prove value quickly and build organizational AI literacy. As usage grows and requirements clarify, they selectively move high-value or high-volume use cases to custom implementations while maintaining managed services for long-tail needs.
This pragmatic approach balances time-to-value with eventual optimization, acknowledging that the right answer today might differ from the right answer in eighteen months.
The Technical Reality of DIY
Building custom AI stacks involves genuine complexity that organizations often underestimate:
The stack typically includes: open-source models (Llama 2, Mistral, or others), vector databases (Pinecone, Weaviate, Chroma) for semantic search, embedding models for converting text to vectors, orchestration frameworks (LangChain, LlamaIndex) for managing prompts and chains, infrastructure for model serving (often GPU-enabled), and monitoring/evaluation systems for tracking performance.
Required expertise spans machine learning engineering, infrastructure operations, prompt engineering, evaluation methodology, and domain knowledge. Organizations need teams that can fine-tune models, optimize inference performance, implement RAG architectures effectively, and maintain systems as models and techniques evolve.
Ongoing operational costs include model hosting infrastructure, storage for vector databases, compute for fine-tuning, engineering time for maintenance and improvements, and evaluation workflows. These costs are real and recurring, though often more predictable than API bills at scale.
Decision Factors
Organizations making this choice should evaluate several dimensions:
Scale of usage fundamentally affects economics. Below 100 users, managed services almost always make sense. Above 10,000 users or millions of requests monthly, DIY economics become compelling.
Technical capability determines feasibility. Organizations without ML engineering talent or unwilling to hire it cannot realistically build and maintain sophisticated AI systems. Managed services may be the only viable option.
Customization requirements influence the choice. If generic AI assistance suffices, managed services work fine. If you need deep domain adaptation or proprietary data integration, custom solutions become necessary.
Security and compliance constraints may force the decision. Highly regulated environments or sensitive data requirements might mandate self-hosted solutions regardless of other factors.
Strategic importance matters. If AI represents core competitive advantage, investing in custom capabilities makes strategic sense. If AI is utility infrastructure, managed services suffice.
The 2024 Outlook
The managed-versus-DIY question will only intensify as both options mature. Managed services will improve integration, capability, and pricing. Open models will close capability gaps while tooling makes custom implementations more accessible.
The likely outcome isn't universal convergence on one approach but continued bifurcation: managed services dominate for general-purpose employee productivity while custom solutions prevail for high-value, high-volume, or highly specialized applications.
The companies that navigate this choice well—matching approach to actual requirements rather than following hype—will extract more value from AI while managing costs and risks appropriately. Those that choose poorly will either overspend on managed services they underutilize or invest in custom solutions they lack the capability to maintain effectively.
The build-versus-buy question never goes away. It just keeps getting more complicated.

