The Soup Kitchen is a vast criminal empire run by The Bowery King in New York, masquerading as a homeless shelter. They have many agents around disguised as homeless people. It was created unaffiliated with the High Table but the Bowery King requested his services to them and they accepted
After experiencing mercy at the hands of a younger John Wick, The Bowery King rose through the ranks to become the head of a vast network of intelligence operatives, covering almost every corner of New York City. This network relies largely on agents in the guise of homeless panhandlers, using access to the city's underground tunnels and passageways to quickly move about with ease.
The Bowery King also manages a flock of homing pigeons, used for secure delivery of messages in the form of microchips or other small objects. Keeping these communications off of the phone lines ensures an additional level of secrecy.
After The Soup Kitchen's main base is decimated by the Adjudicator's mercenary army, the Bowery King and his remaining men go to another base with John Wick to wage war against the High Table.