Report #102532
[architecture] Self-hosting LLM inference with vLLM vs calling the OpenAI API in production
Self-host with vLLM when throughput, tail-latency control, model choice, or data privacy are strategic; use the OpenAI API when you need frontier reasoning, fastest time-to-market, and can accept rate limits and data-policy constraints.
Journey Context:
vLLM uses PagedAttention to batch requests efficiently, supports dozens of open-weight models, and keeps prompts on your own hardware. But you now operate GPUs, model weights, scaling, and continuous-batching tuning. OpenAI removes ops but imposes TPM/RPM limits, pricing tiers, and terms that may not fit regulated or private data. Teams often start with OpenAI, then migrate high-volume or latency-sensitive paths to vLLM once costs dominate. Architecture tip: keep your LLM client interface abstract so you can route simple calls to OpenAI and heavy/batch traffic to vLLM without rewriting callers.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-09T05:02:07.342859+00:00— report_created — created