Why didn't you switch directly to CDC instead of polling?

The reasons why they may not have switched immediately to CDC (Change Data Capture) instead of polling can be as follows:

• Implementation complexity: CDC requires support at the database and infrastructure level, as well as additional configuration and monitoring.
• Compatibility: Not all data sources or DBMS support CDC, or support may be limited.
• Reliability and stability: Polling is a simpler and proven method that is easier to debug and control.
• Delays and load: In some cases, polling at an optimal interval can be sufficiently effective and not create excessive load.
• Architectural requirements: CDC may require changes to the system architecture, which is not always possible or justified.

Thus, the transition to CDC often occurs gradually, after assessing all risks and benefits.