Kainkarya is worshipping Bhagavan Vishnu in utter humility, entirely for His joy with no other motive. According to Sri Vaishnava School of thought, kainkarya is practiced in the highest abode of Bhagavan (Vaikuntha) by innumerable hosts of muktas (liberated souls), nityamuktas (ever-liberated souls) and His consorts.
Amonthe ever-liberated atmas or beings is Ananta Shesha, the primordial serpent who serves his as couch, canopy, seat, pillow, ship in the milky ocean, upper scarf, lamp and so on. Another nityamukta, Gaurda, is the Vahana (vehicle) of Vishnu, who sometimes serves Bhagavan as a throne. Shri Lakshmi is the consort queen of Bhagavan, and attends to him. The only aim of a devout Srivaishnava is to be of some such service to Bhagavan Vishnu.
An extension of the concept is that his kainkarya (complete devotion) becomes more acceptable to Bhagavan when it is rendered to his devotees, called Bhagavatas.
It may be asked how servitude can be the chief aim of human life. The answer is that service abhorred only when it is done to ‘undeserving’ ones. Since Bhagavan alone is the natural master of all living beings, service done to him can never be a source of misery or agony. It may be asked: “Since Bhagavan is always served by such great and powerful devotees as Garuda and Ananta, what further scope is left for an individual self to serve the Lord?”
Srivainshavas believe there may be very little scope for a liberated jiva (individual being) to serve Bhagavan directly. However, he can indirectly serve Bhagavan by being of assistance to the direct servitors of Bhagavan. This is also a source of delight for Bhagavan. Further, it is quite possible that Bhagavan due to his divine will, may allow liberated jivas to serve him in his manifold manifestations, in different ways.