To monitor all of your AWS Lambda functions with Datadog, you can start by enabling Datadog's AWS and Lambda integrations, collecting enhanced metrics and logs, and setting up alerts to detect trends and anomalies. You can also use Datadog's Lambda Library to collect custom business metrics, distributed traces, and enhanced metrics from your functions. With the Lambda extension, you can automatically surface actionable insights into your functions, including detailed metadata for your functions such as cold start and any custom tags you added to your function in the Lambda console. Additionally, you can visualize your AWS Lambda metrics with Datadog's out-of-the-box integration and enhanced metrics dashboards, giving you deep visibility into the performance of your serverless applications.