Senior Architect

Complete toolkit for system design and architecture decisions.

Tech Stack

Languages: TypeScript, JavaScript, Python, Go, Swift, Kotlin
Frontend: React, Next.js, React Native, Flutter
Backend: Node.js, Express, GraphQL, REST APIs
Database: PostgreSQL, Prisma, Supabase
DevOps: Docker, Kubernetes, Terraform, GitHub Actions
Cloud: AWS, GCP, Azure

Architecture Patterns

Monolith vs Microservices

Aspect	Monolith	Microservices
Complexity	Lower initially	Higher, but scales better
Deployment	Single unit	Independent services
Team scaling	Harder beyond 10 devs	Enables team autonomy
Debugging	Easier	Requires distributed tracing

Decision: Start monolith, extract when team/scale demands.

API Design

REST:

• Resource-based URLs (/users, /orders)
• HTTP methods for operations
• Use for CRUD-heavy applications

GraphQL:

• Single endpoint
• Client-specified queries
• Use for complex data requirements

Database Patterns

• Read replicas: Scale read-heavy workloads
• Sharding: Horizontal partitioning for scale
• Event sourcing: Audit trail, temporal queries
• CQRS: Separate read/write models

System Design Process

1. Requirements

• Functional requirements (what it does)
• Non-functional requirements (performance, scale, security)
• Constraints (budget, timeline, team size)

2. High-Level Design

• Component identification
• Data flow mapping
• Integration points

3. Detailed Design

• API contracts
• Database schema
• Error handling
• Caching strategy

4. Trade-offs

• Document decisions with rationale
• Acknowledge what you're giving up
• Plan for future evolution

Diagram Types

C4 Model

1. Context: System and external actors
2. Container: Applications and data stores
3. Component: Internal modules
4. Code: Class-level (rarely needed)

Other Diagrams

• Sequence: Time-ordered interactions
• Data Flow: How data moves through system
• Entity Relationship: Database schema

Best Practices

Code Quality

• Follow established patterns
• Write comprehensive tests
• Document decisions

Performance

• Measure before optimizing
• Use appropriate caching
• Optimize critical paths

Security

• Validate all inputs
• Use parameterized queries
• Implement proper authentication

Maintainability

• Write clear code
• Use consistent naming
• Keep it simple

Output Standards

• Architecture Decision Records (ADRs)
• C4 diagrams in Mermaid format
• System design documents
• API specifications
• Database schema documentation