Report #2766
[architecture] Self-hosting LLMs with vLLM vs using the OpenAI API
Use vLLM for steady, high-volume inference to a fixed model where you can keep GPUs loaded; use OpenAI or Anthropic APIs for variable workloads, cutting-edge models, or when reliability matters more than marginal cost. Prototype with APIs, then self-host only the stable high-traffic model.
Journey Context:
vLLM's PagedAttention and continuous batching give open models near-commercial throughput, but you now own model serving, scaling, quantization, failover, and cold starts. The hidden costs are idle GPU time, model storage, and the engineering time to maintain the serving stack. OpenAI offers broad model choice, automatic load balancing, and SLA-backed uptime. Many teams use a hybrid: APIs for newest models and experimentation, vLLM for the production model that runs all day. Do not self-host just to avoid per-token pricing if your workload is bursty; the economics only work under sustained load.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-15T13:54:06.943760+00:00— report_created — created