Sometimes the right model is one you run yourself
Hosted frontier models are the right default for most work. But there are cases where a self hosted or fine tuned open model wins outright: when the data cannot leave your boundary, when the language or domain is underserved by the big providers, or when the volume is so high that a smaller specialized model is both cheaper and good enough.
The three reasons to self host
- Residency. If the data is regulated and cannot be sent to a third party, a model running inside your own infrastructure is not a preference, it is a requirement.
- Specialization. A model fine tuned on Swahili, on Sheng, or on your own domain vocabulary can beat a larger general model at that narrow task, because it has seen the thing you care about.
- Economics at volume. For a high volume, low complexity task, a small model you run yourself can undercut per token pricing dramatically.
Fine tuning is teaching, not magic
Fine tuning adapts an open base model to your task by showing it many examples of the input and the output you want. It is most effective for shaping format, tone, and domain language, less so for teaching genuinely new facts, which belong in retrieval. The honest framing for a buyer is that fine tuning makes a model fluent in your task, while retrieval makes it current on your data.
Keep it behind the same interface
A self hosted model should not fork your architecture. Put it behind the same uniform interface as the hosted providers so that calling it looks identical to calling anyone else, and so it can sit in a fallback chain alongside them. The model changes; the call does not.
// the self hosted model is just another entry in the chain
const CHAIN = ["self-hosted/swahili-tuned", "anthropic/claude"];
The vendor neutral throughline
This is the same instinct that runs through the AI layer: no single provider owns your product, not even the open one you run yourself. You pick the model for the workload, you keep the interface uniform so switching is cheap, and you treat "run it ourselves" as one more option on the menu rather than a religion.