Bottleneck

A bottleneck is a place in a piece of software which cannot keep up with the rest of the application. It is the slowest part, and also, the limiting portion of the software.

Documentation

See also Top 7 PHP Performance Bottlenecks and How to Monitor Them [2026 Complete Guide] and Monitoring PHP Performance and Diagnosing Bottlenecks.

Related : Just In Time (JIT), Application Performance Management (APM), PHP Profiler