Series: AI Systems at Scale · Part 1 of 5
Building Production Multi-Agent AI Systems: Architecture Patterns
A practical guide to designing multi-agent AI platforms with shared RAG brains, Qdrant vector databases, and FastAPI backends. Lessons from building AImind and Clinic AI at Hureka Technologies.
What is a Multi-Agent AI System?
A multi-agent AI system is a platform where multiple specialized AI agents — each with a distinct role — collaborate to solve complex tasks. Rather than one monolithic AI doing everything, you decompose capabilities: one agent handles email, another manages voice calls, a third orchestrates actions, and a fourth responds to chat.
The architectural challenge is giving all these agents a shared memory and knowledge base without duplicating storage or reprocessing documents for each agent.
The Shared RAG Brain Pattern
The most important architectural decision is the shared RAG (Retrieval-Augmented Generation) brain. Instead of each agent having its own vector database, all agents read from a single Qdrant collection per tenant.
# Agent initialization — all agents share the same Qdrant client
from qdrant_client import QdrantClient
from sentence_transformers import SentenceTransformerqdrant = QdrantClient(host="localhost", port=6333) encoder = SentenceTransformer("all-MiniLM-L6-v2")
def retrieve_context(query: str, tenant_id: str, limit: int = 5): vector = encoder.encode(query).tolist() results = qdrant.search( collection_name=f"tenant_{tenant_id}", query_vector=vector, limit=limit, score_threshold=0.7 ) return [r.payload["text"] for r in results] ```
Agent Specialization with a Unified Interface
Each agent implements a common interface but has specialized system prompts and tools:
class BaseAgent:
def __init__(self, llm_client, tenant_id: str):
self.llm = llm_client
self.tenant_id = tenant_idasync def run(self, user_input: str) -> str: context = retrieve_context(user_input, self.tenant_id) return await self.llm.complete( system=self.system_prompt, context=context, user=user_input )
class EmailAgent(BaseAgent): system_prompt = "You are an email support specialist..."
class VoiceAgent(BaseAgent): system_prompt = "You are a telephone support agent. Keep responses under 2 sentences..." ```
Production Architecture
At Hureka Technologies, our production multi-agent stack uses:
- FastAPI for the API layer with WebSocket support for streaming
- Celery + Redis for async task queues (email processing, background RAG ingestion)
- Qdrant as the vector database with HNSW index for fast similarity search
- Temporal for durable workflow orchestration (critical for multi-step agent tasks)
- LangFuse for LLM observability and cost tracking
Key Lessons from Production
- 1Namespace everything by tenant — Qdrant collection names, Redis keys, Celery queues all include tenant_id
- 2Stream responses — Never block on LLM calls; use FastAPI StreamingResponse
- 3Cache embeddings — Embedding generation is expensive; cache vectors in Redis for repeated queries
- 4Rate limit per tenant — Protect shared infrastructure with per-tenant rate limiting