4.4 Modernization and Enhancements

Decoupling Monoliths

Step Functions vs. SWF

• Step Functions: Visual workflows. State machine. JSON state definition. Modern choice.
• SWF (Simple Workflow Service): Detailed control via code. Older. Used only for prolonged, highly custom flows not supported by Step Functions.

WARNING

Exam Gotcha: Default to Step Functions for orchestration unless specific legacy SWF requirement is mentioned.

Database Modernization

Moving to Managed

• Self-Managed (EC2) → RDS: Automated backups, patching, Multi-AZ.
• RDS → Aurora: Higher performance, Auto-scaling storage, Serverless v2 option.

Heterogeneous Migration (Refactoring)

• Oracle/SQL Server → Aurora PostgreSQL/MySQL: Save license costs.
  • Tool: SCT (Schema) + DMS (Data).
• RDBMS → DynamoDB: High scale key-value access.
  • Challenge: Requires data modeling changes (No Joins).

Serverless Modernization

• Strangler Fig Pattern: Incrementally replace pieces of the monolith with microservices/Lambda until the monolith is gone.