Introduction

For organizations wanting to use generative AI with proprietary data, Retrieval-Augmented Generation (RAG) is a critical architecture. This guide provides a technical walkthrough for building a robust, enterprise-grade RAG pipeline on AWS using Amazon Kendra for retrieval and Amazon Bedrock for generation.

Understanding RAG Architecture

Retrieval-Augmented Generation addresses one of the fundamental challenges in enterprise AI adoption: connecting powerful language models with organization-specific knowledge bases. We identified three key components in effective RAG pipelines:

1. Ingestion Layer: Where enterprise data is processed, transformed, and indexed

2. Retrieval Engine: Which identifies and extracts relevant context based on queries

3. Generative Component: Where language models incorporate retrieved context to produce responses

This architecture significantly reduces the "hallucination problem" common in standard LLM implementations while enabling domain-specific knowledge integration without extensive model retraining.

AWS Implementation Strategy

Our DevDash engineering team has evaluated several cloud-based RAG architectures, finding AWS's combination of Kendra and Bedrock particularly effective for enterprise environments. Here's why:

Amazon Kendra Advantages

• Semantic Search Capabilities: Kendra's ML-powered search extends beyond keyword matching, delivering contextually relevant results

• Multi-format Support: Handles diverse document types from PDFs to Confluence pages

• Enterprise Connectivity: Native integrations with common enterprise systems like SharePoint and Salesforce

• RAG-optimized APIs: The Retrieve API specifically designed for generative AI augmentation

Amazon Bedrock Benefits

• Model Flexibility: Access to multiple foundation models (Anthropic Claude, Amazon Titan) through a unified interface

• Integration Simplicity: Bedrock Knowledge Bases provide streamlined data connections

• Security Compliance: Data remains within your AWS environment, addressing common enterprise security concerns

• Orchestration Tools: Bedrock Flow simplifies complex generative AI pipeline development

Implementation Architecture

Fig i. RAG Pipeline Architecture

The four-stage implementation architecture involves:

1. Data Ingestion

# Example Lambda function for document preprocessing
import boto3

def lambda_handler(event, context):
    textract = boto3.client('textract')
    comprehend = boto3.client('comprehend')

    # Extract text from document
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = event['Records'][0]['s3']['object']['key']
    response = textract.detect_document_text(
        Document={'S3Object': {'Bucket': bucket, 'Name': key}}
    )
    text = " ".join([item['Text'] for item in response['Blocks'] if item['BlockType'] == 'LINE'])

    # Enrich metadata
    entities = comprehend.detect_entities(Text=text, LanguageCode='en')
    
    return {
        'text': text,
        'metadata': entities['Entities']
    }

This stage includes:

• Document storage in S3

• Text extraction using AWS Textract

• Metadata enrichment with AWS Comprehend

• Indexing via Kendra's BatchPutDocument API

2. Context Retrieval

When a query arrives, the system retrieves relevant context:

response = kendra.retrieve(
    IndexId='your-index-id',
    QueryText='What is the company's remote work policy?'
)

for passage in response['Passages']:
    print(f"Passage: {passage['PassageText']}")

Our testing shows Kendra's semantic search capabilities significantly outperform traditional vector databases for complex enterprise queries.

3. Augmented Generation

The DevDash approach uses LangChain for orchestration between retrieval and generation:

from langchain.chains import RetrievalQA
from langchain.llms import BedrockLLM
from langchain.vectorstores import AmazonKendraRetriever

# Set up retriever
retriever = AmazonKendraRetriever(index_id="your-index-id")

# Set up LLM from Bedrock
llm = BedrockLLM(model="amazon-titan")

# Create RAG pipeline
qa_chain = RetrievalQA(llm=llm, retriever=retriever)

# Query example
query = "What is the company's remote work policy?"
response = qa_chain.run(query)

4. Response Delivery

The final component formats responses for consumption:

{
  "question": "What is the company's remote work policy?",
  "answer": "The company allows remote work up to three days per week.",
  "sources": [
    {
      "title": "Remote Work Policy",
      "url": "https://s3.amazonaws.com/yourbucket/doc1.pdf"
    }
  ]
}

DevDash Best Practices

Our implementation research has identified several critical success factors:

1. Optimize Document Chunking

Testing shows that chunking documents into 500-word segments optimizes retrieval precision. Larger chunks reduce contextual relevance while smaller chunks fragment conceptual integrity.

2. Implement Metadata Filtering

Organizations should develop a comprehensive metadata strategy during ingestion.

3. Secure Your Pipeline

Enterprise RAG implementations require comprehensive security measures:

• IAM role-based access controls

• KMS encryption for data at rest and in transit

• VPC isolation for sensitive workloads

4. Monitor Performance Metrics

Tracking key performance indicators helps optimize RAG pipelines:

• Query latency trends

• Retrieval precision/recall metrics

• Model performance comparisons

Conclusion

Our research demonstrates that AWS Kendra and Bedrock provide a robust foundation for enterprise RAG implementations. This architecture enables organizations to leverage their proprietary data with generative AI while maintaining security, scalability, and accuracy.

As generative AI continues to transform enterprise operations, properly implemented RAG pipelines will be essential for organizations seeking to extract maximum value from their data assets while minimizing the risks associated with pure LLM implementations.

While this architecture provides a powerful foundation, applying it to your unique data and security requirements requires a clear strategy. If you need help tailoring this framework to your business, our 90-minute AI workshop is designed to build a custom implementation roadmap.