“Build with LLM vs Buy” will undoubtably fall into the same patterns of most in-house built solutions. The early stages are always easier, and the wins come fast.

• Easy: spin up “working” proof of concept (v0.1)
• Easy: iterate towards the current v1.0 with limited feature set
• Intermediate : Fix bugs, respond to internal customer feedback, add more features (v1.1 to v1.x)
• Intermediate: Performance improvements, scaling
• Hard: Address security vulnerabilities
• Hard: Integrating into a broader and more diverse software ecosystem (internal or external systems)

Depending on the usefulness of this in-house solution, you will need engineers to maintain it or at least, understand it so they can shovel more prompts to the LLM to address. It doesn’t come for free, and it will usually be a secondary workstream to your primary business.