InstructID

AI Infrastructure 101

A practical guide to setting up the infrastructure needed for AI applications — from model serving to monitoring and cost optimization.

ai harnessIntermediateby InstructID Team··2 min read
infrastructuredeploymentmlops

Why AI Infrastructure Matters

Building an AI application is only half the battle. Getting it to production — reliably, efficiently, and cost-effectively — requires thoughtful infrastructure design.

Core Components

Model Serving

The foundation of any AI application is how you serve your models. Common approaches include:

  • API-based: OpenAI, Anthropic, Google — easiest to start, pay-per-use
  • Self-hosted: vLLM, Ollama, TGI — more control, higher upfront cost
  • Serverless: AWS Lambda + model endpoints — scalable, cold start concerns

Vector Databases

For RAG applications, you'll need a vector store. Here's a quick comparison:

DatabaseBest ForHosting
PineconeProduction, managedCloud
WeaviateFlexible, open sourceSelf-hosted / Cloud
ChromaDBLocal dev, prototypingLocal / Embedded
QdrantHigh performanceSelf-hosted / Cloud

Example: Simple RAG Pipeline

from langchain.embeddings import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.chains import RetrievalQA
from langchain.llms import OpenAI
 
embeddings = OpenAIEmbeddings()
vectorstore = Chroma.from_documents(documents, embeddings, persist_directory="./db")
 
qa = RetrievalQA.from_chain_type(
    llm=OpenAI(),
    retriever=vectorstore.as_retriever(search_kwargs={"k": 3})
)
 
result = qa.run("How do I set up vector embeddings?")
print(result)

Cost Optimization

Key strategies for keeping costs under control:

  1. Cache responses — avoid re-computing for repeated queries
  2. Use smaller models — not everything needs GPT-4
  3. Batch requests — reduce API overhead
  4. Monitor usage — set up alerts for unexpected spikes
  5. Optimize prompts — shorter prompts = lower costs

Monitoring

Track these key metrics:

  • Latency (p50, p95, p99)
  • Error rates
  • Token usage per request
  • Cost per query
  • Cache hit ratio