Functional vs Non-Functional Requirements

🟢 LEVEL 1 — Foundations

1. Requirements Overview

• What are requirements
• Business vs technical requirements
• Functional requirements (FR)
• Non-functional requirements (NFR)
• Importance of clear requirement classification

🟢 LEVEL 2 — Functional Requirements Basics

2. Functional Requirements Definition

• System behaviors
• Feature capabilities
• User interactions
• Business rules

3. Types of Functional Requirements

• Core features
• Optional features
• Edge case handling
• Error handling behavior

🟡 LEVEL 3 — Functional Documentation

4. User Stories

• As a / I want / So that
• Acceptance criteria
• Use cases
• User flows

5. Functional Validation

• Expected inputs
• Expected outputs
• Business logic validation

🔵 LEVEL 2 — Non-Functional Requirements Basics

6. NFR Definition

• Quality attributes
• System constraints
• Performance expectations

7. Categories of NFRs

• Performance
• Scalability
• Reliability
• Security
• Usability
• Accessibility
• Maintainability
• Compatibility
• Portability

🔵 LEVEL 3 — Performance & Scalability

8. Performance Requirements

• Response time
• Throughput
• Concurrent users
• Load handling

9. Scalability Requirements

• Horizontal scaling
• Vertical scaling
• Future growth planning

🟠 LEVEL 4 — Security & Compliance

10. Security Requirements

• Authentication
• Authorization
• Data encryption
• Data privacy

11. Compliance Requirements

• Regulatory standards
• Data residency
• Audit logging

🟠 LEVEL 5 — Reliability & Availability

12. Reliability

• Fault tolerance
• Retry mechanisms
• Error recovery

13. Availability

• SLA targets
• Uptime percentage
• Disaster recovery

🔴 LEVEL 6 — Requirement Translation to Architecture

14. Mapping FR to Technical Design

• Feature → API mapping
• Feature → Component mapping
• Feature → Data model mapping

15. Mapping NFR to Architecture

• Performance → Caching
• Scalability → Load balancing
• Security → Auth design
• Reliability → Circuit breakers

🟣 LEVEL 7 — Senior Engineer Thinking

16. Trade-off Analysis

• Feature richness vs performance
• Speed of delivery vs maintainability
• Scalability vs cost

17. Early NFR Identification

• Detecting hidden NFRs
• Identifying scalability risks
• Identifying security risks

18. Validation & Measurement

• KPIs for FR
• Metrics for NFR
• Monitoring & observability alignment