That would be a Studor valve. And probably good depending on local codes. There are horizontal distance restrictions when you're under a window and need to vent sideways.

BTW: hopefully that wasnt a stand pipe for the DW. Did it have a trap at the bottom? If not, it never should have passed inspection.

Can use an air admittance valve if impractical to run a vent line for a kitchen sink. Cheap. Must be in an accessible location(not behind drywall) Valve opens when senses suction, otherwise closed. Generally have very long life but not permanent like passive vent line.