Purpose
To provide a standardized architecture blueprint that documents how business and technical requirements are translated into a working system design.
This ensures developers, architects, and stakeholders have a shared, high-level view of system components, interactions, and constraints.
Structure
Section 1 – Project Context
| Field | Example (B2B SaaS) | Example (B2C App) |
| Project Name | SaaS Onboarding Automation | EcoClean Booking App |
| Business Goal | Reduce churn by improving onboarding workflows | Enable families to book verified eco-friendly cleaners |
| Core Users | SaaS CTOs, Customer Success Managers | Urban families, busy professionals |
| Key Outcomes | Churn ↓ 30%, Adoption ↑ 40% | Time saved, Safer verified cleaning |
Section 2 – High-Level Architecture Overview
| Component | Description | Example (SaaS) | Example (B2C) |
| Frontend | User-facing app/web | React web app | Flutter mobile app |
| Backend | Core APIs & business logic | Node.js + Express | Firebase Functions |
| Database | Data storage layer | PostgreSQL | Firestore |
| Auth & Security | Identity management | Auth0 (OIDC) | Firebase Auth |
| Integrations | Third-party systems | Salesforce API | Google Maps API |
| Infrastructure | Hosting & runtime | AWS ECS + RDS | GCP Firebase Hosting |
Section 3 – System Modules
| Module | Function | Example (SaaS) | Example (B2C) |
| User Management | Auth, roles, profiles | Auth0 + RBAC | Firebase Auth |
| Core Feature | Main business logic | Workflow engine for onboarding | Booking engine |
| Payments | Billing & invoicing | Stripe API | Razorpay |
| Notifications | Email, SMS, Push | SendGrid, Twilio | Firebase Cloud Messaging |
| Analytics | Usage tracking & reporting | Mixpanel + BI dashboard | Google Analytics + custom reporting |
Section 4 – Data Flows
| Flow | Trigger | Source → Destination | Example |
| User Signup | New user registers | Frontend → Backend → DB | React form → Node API → PostgreSQL |
| Booking Request | User books service | App → API → DB → Notification | Flutter app → Firebase Function → Firestore → Push |
| Payment Flow | Checkout | Frontend → Payment Gateway → DB | Web → Stripe → RDS |
Section 5 – Non-Functional Requirements
| Category | Requirement | Example |
| Scalability | Handle 10K concurrent users | Horizontal scaling on AWS ECS |
| Availability | 99.9% uptime | Multi-zone hosting |
| Security | Enforce RBAC, encrypt PII | GDPR & SOC2 alignment |
| Performance | <200ms API latency | API caching layer |
| Monitoring | Real-time logs + alerts | Datadog, Grafana |
Section 6 – Risks & Constraints
| Risk/Constraint | Impact | Mitigation |
| Vendor Lock-In | Tied to Auth0 for auth | Abstract auth layer |
| Budget Constraint | Infra costs high at scale | Optimize with reserved instances |
| Compliance | Must be GDPR-compliant | Use EU data region |
Blank Reusable Template
Project Context
| Field | Entry |
| Project Name | |
| Business Goal | |
| Core Users | |
| Key Outcomes |
High-Level Architecture Overview
| Component | Description | Tool/Tech Stack |
System Modules
| Module | Function | Tool/Tech Stack |
Data Flows
| Flow | Trigger | Source → Destination | Notes |
Non-Functional Requirements
| Category | Requirement |
Risks & Constraints
| Risk/Constraint | Impact | Mitigation |