Editing ChromaDB vs. FastEmbed for SaaS RAG

When building a SaaS RAG (Retrieval-Augmented Generation) platform, priorities shift from just “getting embeddings” to:
* 		🚀 Low latency (fast responses)
* 		🔐 Multi-tenancy (firm-level data isolation)
* 		💰 Cost efficiency (handling lots of PDFs without breaking the bank)
Two popular tools come up a lot in this space: ChromaDB and FastEmbed. Let’s see where each fits in your SaaS architecture.
Using ChromaDB in SaaS RAG
Pros:
* 		Open-source, runs in-process (like SQLite but for vectors).
* 		Great for quick prototyping & small/mid-scale tenants.
* 		Easy to store metadata like tenant_id, product_type, etc.
* 		Can persist to disk or use external backends like Postgres.
Cons:
* 		Single-node by default (limited scaling).
* 		With 100s of firms + millions of chunks, performance may degrade.
✅ Best Fit: Small to medium SaaS deployments where you control infra and want to keep costs low.

Using FastEmbed
FastEmbed isn’t a DB — it’s a fast embedding generator.
Pros:
* 		Blazing fast embedding generation (optimized for CPU).
* 		No reliance on external APIs (unlike OpenAI) → big cost savings.
* 		Ideal for PDF ingestion pipelines (lots of docs from tenants).
Cons:
* 		Only creates embeddings → you still need a vector DB (Chroma, Qdrant, Pinecone, PGVector).
✅ Best Fit: Embedding pipeline stage in SaaS → compute embeddings locally, then store in Chroma or Qdrant.

Recommended SaaS Setup
Here’s how a multi-tenant SaaS RAG stack could look:

[[file:Here’s_how_a_multi-tenant_SaaS_RAG.jpg|650px]]

Figure: System Flow

PDF Ingestion & Embeddings
<pre>
from fastembed.embedding import TextEmbedding

# Step 1: Initialize FastEmbed
model = TextEmbedding()

# Step 2: Generate embeddings for chunks
embeddings = model.embed(["Some chunk of text"])
</pre>

🔹 Store in ChromaDB (per-tenant collection)
<pre>
import chromadb

# Create persistent DB for tenant firm123
client = chromadb.PersistentClient(path="db/policies_docs")
collection = client.get_or_create_collection("tenant_firm123")

# Add document chunks
collection.add(
    documents=["Requirement text..."],
    embeddings=embeddings,
    metadatas=[{"tenant_id": "firm123", "page": 5}],
    ids=["chunk1"]
)
</pre>

🔹 Multi-tenant Query Filtering
<pre>
results = collection.query(
    query_texts=["What are H-1B requirements?"],
    n_results=3,
    where={"tenant_id": "firm123"}  # 🔐 Tenant isolation
)
</pre>

⚡ Best Practice for SaaS
* 		✅ Use FastEmbed for fast, cheap embeddings.
* 		✅ Use ChromaDB for MVPs or early SaaS (per-tenant collections).
* 		✅ Migrate to Qdrant Cloud / Pinecone once scale increases.
* 		✅ Always filter by tenant_id to prevent cross-firm data leaks.
🎯 Final Takeaway
* 		ChromaDB = lightweight, perfect for MVPs.
* 		FastEmbed = cost-efficient embedding engine.
* 		Qdrant / Pinecone = scale-ready vector DB for production.
👉 For SaaS, the winning combo is:
* 		MVP → ChromaDB + FastEmbed
* 		Scaling → Qdrant + FastEmbed

Read the full article here: https://subhojyoti99.medium.com/chromadb-vs-fastembed-for-saas-rag-4f4b1494bb1c