Greg Wester introduces Apex Realtime Debugger, a new tool that allows developers to debug Apex code and triggers live in sandboxes and production environments. It instruments the platform to observe Apex code execution and provides unit tests, debug logs, and an interactive debugger. This helps developers reproduce and fix bugs that may only appear in complex sandbox and production environments due to differences from developer orgs in metadata, data, and managed code. The debugger can be used to debug async Apex code and works like a local debugger with a dedicated leased line session. It is generally available with licenses assigned per org and can be trialed.