Do I need model serving infrastructure if I'm just calling an API?

Not usually.

If you’re just calling a hosted API like OpenAI, Anthropic, or another managed model provider, then you do not need to build or operate model serving infrastructure yourself. The provider handles:

• model hosting
• scaling
• GPU management
• load balancing
• updates and reliability
• inference optimization

What you do still need depends on your app:

You may only need:

• a backend/server to make API calls securely
• rate limiting / retries
• request logging and monitoring
• secret management for API keys

You would need model serving infrastructure if:

• you want to host your own model
• you need on-prem / air-gapped deployment
• you want lower latency or lower cost at scale
• you need custom control over model versions, batching, quantization, or routing
• you’re running open-source models like Llama locally or in your cloud

Simple rule

• Using someone else’s API → no model serving infra needed
• Running your own model → yes, you need serving infra

If you want, I can also sketch the difference between application backend, model serving, and MLOps in one diagram.