Worked on the espressif/esp-usb repository to address a deep sleep leakage issue affecting the USB HS PHY when using the UTMI PHY. The solution involved registering a hook in C to suppress leakage during deep sleep, directly improving power management and stability during low-power transitions after USB initialization. This fix reduced unwanted wakeups caused by leakage, enhancing the reliability of the USB subsystem in embedded systems. The work demonstrated a strong focus on hardware support and low power modes, applying embedded systems expertise to refine device behavior during critical power state changes without introducing new features during the development period.