Harness's guide explores how Java developers can streamline feature management and conduct A/B tests using Split's Java SDK for feature flags. The SDK allows developers to manage features without directly interacting with the underlying API, integrating easily with tools like Maven or Gradle for setup. By creating a long-lived feature flags client, developers can effectively manage different code paths and treatments, such as introducing new payment methods or testing database performance with dark writes. Split also provides capabilities like a kill switch for disabling features and serves as an on/off toggle for feature testing. The platform's feature management tools enable safe and rapid deployment, connecting feature flags to contextual data to evaluate their impact on performance. Split aims to enhance development workflows by allowing controlled feature releases and experimentation while minimizing risk and downtime.