Report #727
[architecture] Self-hosting LLMs with vLLM vs calling OpenAI: when does owning inference infrastructure actually pay off?
Start with OpenAI, Anthropic, or another managed API while you are iterating, have unpredictable traffic, or need frontier models. Move to vLLM self-hosting only when you have steady high token volume, strict data-sovereignty or privacy requirements, or latency needs that demand GPUs in your own region. Deploy vLLM with its OpenAI-compatible API server so your client code, retries, and routing logic stay portable between self-hosted and managed models.
Journey Context:
vLLM's PagedAttention and continuous batching can deliver far higher throughput than naive Hugging Face serving, but the savings only materialize if the GPUs stay busy. Idle GPU time destroys the cost advantage of self-hosting. You also take on drivers, CUDA, quantization, model licensing, load balancing, failover, scaling, and security patching. Managed APIs charge a premium per token but remove all of that operational risk and give you instant access to the best models. The wrong move is self-hosting a small model to 'save money' at low volume; the right move is using vLLM as a high-throughput, sovereign inference tier behind the same OpenAI-compatible interface you already use.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-13T11:57:40.831542+00:00— report_created — created