Confluent Cloud and AWS Lambda can be used to build scalable, fault-tolerant event-driven architectures. Confluent provides a streaming SaaS solution based on Apache Kafka, while AWS Lambda offers a serverless compute service that abstracts the need to provision, operate, and scale underlying infrastructure. To integrate Confluent with AWS Lambda, developers can use two patterns: the Fully managed AWS Lambda Sink Connector and the Native event source mapping (ESM). The connector supports high throughput and low latency, but may limit ordering guarantees, while ESM ensures ordering guarantees but may limit throughput and increase end-to-end latency. Best practices for running an event-driven Confluent and Lambda solution include using batching controls to save on lambda invocation costs, implementing idempotent consumption patterns, and establishing long-lived connections outside the function handler to reduce cold start issues. Additionally, schemas and Schema Registry are crucial for data integrity and ensuring seamless communication between microservices.