Build vs Buy: Choosing Your LLM Key Management Solution

Every engineering team eventually faces the build versus buy decision for key management. Building provides maximum customization but requires ongoing investment. Buying provides faster time to value but less control. The right choice depends on your specific situation, and the factors that matter most aren't always obvious.

The Temptation to Build

Building your own solution is appealing for several reasons, some valid and some misleading.

Perfect fit for your needs is the most compelling argument. Custom solutions can match your exact workflow, integrate with your specific infrastructure, and omit features you don't need. No compromises, no workarounds.

Perceived cost savings attract teams with strong engineering capabilities. If you already have engineers on staff, building seems free compared to paying for external tools. This perception often proves incorrect when total costs are calculated.

Control and independence mean you're not dependent on external vendors. No risk of vendor shutdown, price increases, or feature changes that don't align with your needs. Everything is within your control.

Learning and capability building provide value beyond the immediate tool. Building key management infrastructure teaches your team about security, cryptography, and systems design. This knowledge has value even if the specific tool eventually gets replaced.

The Hidden Costs of Building

The appeal of building often obscures significant costs that become apparent only later.

Initial development time is usually underestimated. A basic key-value store with encryption takes days. Adding proper access controls, audit logging, and environment handling takes weeks. Building a robust, production-ready system takes months.

Ongoing maintenance never ends. Security updates, bug fixes, feature additions, and infrastructure maintenance all require ongoing attention. Unlike product features that ship and are done, infrastructure requires continuous investment.

Opportunity cost is the work your team isn't doing while building and maintaining key management. Every hour spent on infrastructure is an hour not spent on your core product. For most companies, product advancement creates more value than infrastructure building.

Security responsibility shifts entirely to you. When you build your own security infrastructure, you own the consequences of any vulnerabilities. External solutions spread this responsibility and often have dedicated security teams.

Knowledge concentration creates risk when key people leave. If one engineer built your key management system and they depart, you might lack the expertise to maintain or extend it effectively.

When Building Makes Sense

Despite the costs, building is the right choice in some circumstances.

Unique requirements that no existing solution addresses might justify custom development. If your workflow, compliance needs, or integration requirements are genuinely unusual, building might be the only option.

Core competency alignment matters. If security infrastructure is central to your value proposition, building expertise in this area makes strategic sense. Security companies should probably build; application companies probably shouldn't.

Scale economics change the calculation at very high volumes. If you're managing thousands of credentials across dozens of applications, custom infrastructure might provide efficiency that general-purpose tools can't match.

Existing infrastructure to leverage reduces the build cost. If you already have secrets management, encryption infrastructure, and access control systems, adding LLM-specific features might be incremental rather than ground-up.

When Buying Makes Sense

For most teams, buying provides better value than building.

Faster time to value means you're secured now rather than in months. Every day without proper key management is a day of accumulated risk. Adoption gets you protected immediately.

Lower total cost results from spreading development and maintenance across many customers. Managed solutions can invest in capabilities that would be uneconomical for individual teams to build.

Specialized expertise is difficult to build internally. Key management touches security, cryptography, compliance, and infrastructure. External solutions bring deep expertise in all these areas.

Reduced maintenance burden frees your team to focus on your core product. When someone else handles security updates, feature additions, and infrastructure operations, your engineers build features your customers want.

Evaluating External Solutions

If you decide to buy, several factors help evaluate options.

Feature alignment should match your actual needs. Don't pay for enterprise features you won't use. Don't choose solutions that lack capabilities you need. List your requirements and evaluate against them.

Security posture matters critically for something that stores your credentials. How is data encrypted? What certifications does the provider have? What happens if they're breached?

Integration capabilities determine how easily the solution fits your existing infrastructure. API quality, SDK availability, and compatibility with your stack all affect adoption effort.

Pricing model should align with your usage patterns. Per-credential pricing works for some teams. Per-user pricing works for others. Understand how your usage maps to costs.

Vendor viability affects long-term risk. Established companies with sustainable business models are safer bets than early-stage startups that might disappear.

The Hybrid Approach

Many teams find a middle ground that combines external solutions with custom extensions.

Core functionality from managed solutions provides the foundation. Encryption, storage, access control, and audit logging come from the external platform.

Custom integrations connect the managed solution to your specific infrastructure. Deployment pipeline integration, monitoring hooks, and workflow automation might be built internally.

Wrapper layers add organization-specific behavior. Custom mock mode handling, environment detection logic, or access patterns might wrap the external API.

This approach captures most benefits of buying while allowing customization where it matters most to your organization.

Making the Decision

Several questions help clarify the right choice.

Is key management core to your competitive advantage? If no, buying is probably right.

Do you have unique requirements no existing solution addresses? If no, buying is probably right.

Do you have dedicated security engineering capacity? If no, buying is definitely right.

Are you optimizing for speed or control? Speed favors buying. Control favors building.

What's your realistic maintenance budget for the next three years? If limited, buying is right.

The build versus buy decision for key management is ultimately about where your team creates the most value. Most teams create value through their products, not through their infrastructure. For them, buying enables focus on what matters most while ensuring credentials are managed securely.