senior-architect

System architecture — ADRs, tech-stack evaluation, design review.

SKILL.md

GitHub

Senior Architect

Architecture design and analysis tools for making informed technical decisions.


Tools Overview

1. Architecture Diagram Generator

Generates architecture diagrams from project structure in multiple formats.

Solves: "I need to visualize my system architecture for documentation or team discussion"

Input: Project directory path Output: Diagram code (Mermaid, PlantUML, or ASCII)

Supported diagram types:

  • component - Shows modules and their relationships
  • layer - Shows architectural layers (presentation, business, data)
  • deployment - Shows deployment topology

Usage:

# Mermaid format (default)
python scripts/architecture_diagram_generator.py ./project --format mermaid --type component

# PlantUML format
python scripts/architecture_diagram_generator.py ./project --format plantuml --type layer

# ASCII format (terminal-friendly)
python scripts/architecture_diagram_generator.py ./project --format ascii

# Save to file
python scripts/architecture_diagram_generator.py ./project -o architecture.md

Example output (Mermaid):

graph TD
    A[API Gateway] --> B[Auth Service]
    A --> C[User Service]
    B --> D[(PostgreSQL)]
    C --> D

2. Dependency Analyzer

Analyzes project dependencies for coupling, circular dependencies, and outdated packages.

Solves: "I need to understand my dependency tree and identify potential issues"

Input: Project directory path Output: Analysis report (JSON or human-readable)

Analyzes:

  • Dependency tree (direct and transitive)
  • Circular dependencies between modules
  • Coupling score (0-100)
  • Outdated packages

Supported package managers:

  • npm/yarn (package.json)
  • Python (requirements.txt, pyproject.toml)
  • Go (go.mod)
  • Rust (Cargo.toml)

Usage:

# Human-readable report
python scripts/dependency_analyzer.py ./project

# JSON output for CI/CD integration
python scripts/dependency_analyzer.py ./project --output json

# Check only for circular dependencies
python scripts/dependency_analyzer.py ./project --check circular

# Verbose mode with recommendations
python scripts/dependency_analyzer.py ./project --verbose

Example output:

Dependency Analysis Report
==========================
Total dependencies: 47 (32 direct, 15 transitive)
Coupling score: 72/100 (moderate)

Issues found:
- CIRCULAR: auth → user → permissions → auth
- OUTDATED: lodash 4.17.15 → 4.17.21 (security)

Recommendations:
1. Extract shared interface to break circular dependency
2. Update lodash to fix CVE-2020-8203

3. Project Architect

Analyzes project structure and detects architectural patterns, code smells, and improvement opportunities.

Solves: "I want to understand the current architecture and identify areas for improvement"

Input: Project directory path Output: Architecture assessment report

Detects:

  • Architectural patterns (MVC, layered, hexagonal, microservices indicators)
  • Code organization issues (god classes, mixed concerns)
  • Layer violations
  • Missing architectural components

Usage:

# Full assessment
python scripts/project_architect.py ./project

# Verbose with detailed recommendations
python scripts/project_architect.py ./project --verbose

# JSON output
python scripts/project_architect.py ./project --output json

# Check specific aspect
python scripts/project_architect.py ./project --check layers

Example output:

Architecture Assessment
=======================
Detected pattern: Layered Architecture (confidence: 85%)

Structure analysis:
  ✓ controllers/  - Presentation layer detected
  ✓ services/     - Business logic layer detected
  ✓ repositories/ - Data access layer detected
  ⚠ models/       - Mixed domain and DTOs

Issues:
- LARGE FILE: UserService.ts (1,847 lines) - consider splitting
- MIXED CONCERNS: PaymentController contains business logic

Recommendations:
1. Split UserService into focused services
2. Move business logic from controllers to services
3. Separate domain models from DTOs

Decision Workflows

Database Selection Workflow

Use when choosing a database for a new project or migrating existing data. For the SQL/NoSQL decision matrix, database type comparisons, and quick decision flow, see references/tech_decision_guide.md (§1 Database Selection).

Document the decision: Create an ADR (Architecture Decision Record) with:

  • Context and requirements
  • Options considered
  • Decision and rationale
  • Trade-offs accepted

Architecture Pattern Selection Workflow

Use when designing a new system or refactoring existing architecture.

Step 1: Assess team and project size

Team Size Recommended Starting Point
1-3 developers Modular monolith
4-10 developers Modular monolith or service-oriented
10+ developers Consider microservices

Step 2: Evaluate deployment requirements

  • Single deployment unit acceptable → Monolith
  • Independent scaling needed → Microservices
  • Mixed (some services scale differently) → Hybrid

Step 3: Consider data boundaries

  • Shared database acceptable → Monolith or modular monolith
  • Strict data isolation required → Microservices with separate DBs
  • Event-driven communication fits → Event-sourcing/CQRS

Step 4: Match pattern to requirements

Requirement Recommended Pattern
Rapid MVP development Modular Monolith
Independent team deployment Microservices
Complex domain logic Domain-Driven Design
High read/write ratio difference CQRS
Audit trail required Event Sourcing
Third-party integrations Hexagonal/Ports & Adapters

See references/architecture_patterns.md for detailed pattern descriptions.


Monolith vs Microservices Decision

See references/architecture_patterns.md (§1–3 + decision table) — when-to-use criteria and the extract-when rule live there.


Reference Documentation

Load these files for detailed information:

File Contains Load when user asks about
references/architecture_patterns.md 9 architecture patterns with trade-offs, code examples, and when to use "which pattern?", "microservices vs monolith", "event-driven", "CQRS"
references/system_design_workflows.md 6 step-by-step workflows for system design tasks "how to design?", "capacity planning", "API design", "migration"
references/tech_decision_guide.md Decision matrices for technology choices "which database?", "which framework?", "which cloud?", "which cache?"

Tech Stack Coverage

Languages: TypeScript, JavaScript, Python, Go, Swift, Kotlin, Rust Frontend: React, Next.js, Vue, Angular, React Native, Flutter Backend: Node.js, Express, FastAPI, Go, GraphQL, REST Databases: PostgreSQL, MySQL, MongoDB, Redis, DynamoDB, Cassandra Infrastructure: Docker, Kubernetes, Terraform, AWS, GCP, Azure CI/CD: GitHub Actions, GitLab CI, CircleCI, Jenkins