You would use Apache Kafka when you need a robust system for handling real-time data streams with high throughput and low latency. A specific scenario would be in a large e-commerce platform where you need to process orders in real-time to update inventory, send notifications, and analyze customer behavior instantly. In this case, Kafka can handle multiple order events at scale without data loss.
Talend is ideal for organizations that need a comprehensive ETL tool to handle complex data transformation and integration tasks with a user-friendly interface. It is particularly useful when the data needs to be cleaned, transformed, or aggregated, such as during the process of moving data from multiple legacy databases into a data warehouse for reporting. A specific scenario would be migrating data from an on-premise SQL database to a cloud-based data warehouse while performing necessary transformations along the way.