➀ Signal Integrity (SI) issues in PCB and package design; ➁ Waveform distortions and time delays; ➂ Types of signal integrity problems like overshoot and ISI; ➃ Transmission line modeling and microstrip/stripline examples; ➄ Minimizing discontinuities and managing reflections; ➅ Mitigating crosstalk and via performance; ➆ Timing and skew considerations in high-speed digital designs.