Architecture
Deep dive into the system architecture, design decisions, and technical details.
Overview
This section explains how the NorthBuilt RAG System is architected, why certain technologies were chosen, and how much it costs to operate.
Documents
1. System Architecture
Complete technical architecture with component diagrams and data flow.
- Component breakdown (Lambda, API Gateway, Bedrock, S3 Vectors)
- Data flow diagrams
- Scalability and disaster recovery
- Performance characteristics
Audience: Engineers, Architects Time: 30 minutes
2. Cost Analysis
Monthly cost breakdown and optimization strategies.
- Base infrastructure costs (~$137/month)
- Usage-based costs (Bedrock tokens)
- Cost optimization strategies
- Comparison with alternatives
- Break-even analysis
Audience: Engineering Managers, Finance, Architects Time: 20 minutes
3. Security
Security architecture and compliance.
- Authentication & authorization
- Data encryption (at rest and in transit)
- Network security
- Incident response procedures
- Compliance (SOC 2, GDPR)
Audience: Security Engineers, Compliance Time: 25 minutes
4. Architecture Decision Records
Why we made key technical decisions.
- ADR-001: Serverless on Lambda
- ADR-002/006/010: Vector storage evolution (S3 Vectors)
- ADR-003: Claude Sonnet 4.5 for LLM
- ADR-004: Cognito + Google OAuth
- And 5 more decisions documented
Audience: All engineers, Architects Time: 15 minutes
Recommended Reading Order
For New Engineers: System Architecture → Security → ADRs For Cost Analysis: Cost Analysis → ADRs (see alternatives considered) For Security Review: Security → System Architecture → ADRs
Key Takeaways
- 100% Serverless: No servers to manage, auto-scaling, pay-per-use
- Cost-Effective: ~$140/month for moderate usage (1K queries)
- High Performance: <2s end-to-end query latency, <25ms vector search
- Secure by Design: Multi-layer security, encryption everywhere, IAM least-privilege
Next: Operations Guide to deploy and maintain the system.