Architecture focuses on high-level structure and major components:

• System-wide decisions and constraints
• Technology choices and frameworks
• Component relationships and interfaces
• Non-functional requirements (performance, security)
  Design focuses on detailed implementation:
• Class structures and method signatures
• Algorithms and data structures
• Implementation-specific patterns
• Code organization within components
  Example:
• Architecture: "We'll use microservices with REST APIs and a message queue"
• Design: "The UserService class will have a getUserById() method that queries PostgreSQL"