Just like in the P20 Pro, the USB-C charging port is mounted to a large flex cable. This means if the charging port fails, you'll only have to replace the main cable—instead of a more expensive daughterboard, as in the Google Pixel 3 XL.
Another similarity to the P-Series: no 3.5 mm headphone jack. USB-C headphones are included along with a 3.5 mm adapter.
The other port, a SIM reader, is mounted to a small board, and planted near the coin-style vibration motor.