Introducing key tools, techniques, and best practices for improving the performance of X++ customizations in D365FO. Covering the use of analysis tools such as Trace Parser and SQL Profiler to identify performance bottlenecks, along with practical tips for optimizing database access and refactoring code structures. The goal is to provide developers with a clear, actionable approach to detect performance issues early and implement efficient coding patterns to ensure a high-performing and scalable system.