What is pressure profiling in espresso?

Pressure profiling means varying the pressure throughout the shot rather than maintaining constant 9 bar. For example, a declining pressure profile might start at 6 bar and finish at 4 bar — this is said to reduce over-extraction in the final stages and enhance sweetness. Machines like the Decent Espresso DE1 and Lelit Bianca offer programmable pressure profiles. Most home baristas don't need pressure profiling, but it's a fascinating advanced tool for optimizing specific beans.