Integrating load testing into CI pipelines using Grafana k6 and CircleCI can help catch performance issues early and improve application reliability. The process involves writing a k6 performance test script, configuring thresholds for service-level objectives (SLOs), and setting up a CircleCI pipeline with a configuration file that triggers builds upon repository changes. CircleCI orbs, such as grafana/k6, streamline the test execution. Tests can be run locally or on Grafana Cloud for larger or geographically distributed loads, requiring a Grafana Cloud account and API token for cloud tests. The tutorial explains how to store test results as artifacts, schedule nightly builds using crontab syntax, and handle test summaries with k6's handleSummary function. Additionally, it demonstrates the use of k6 extensions, which are Go-based and can be run in a Docker environment, offering further customization for load testing needs. The tutorial emphasizes the importance of defining performance thresholds and using CircleCI's artifact storage for detailed analysis, while also highlighting the ease of starting with Grafana Cloud.