This is the 12100th most frequent Spanish word.
instantáneo
Instantaneous; occurring or done instantly.
Here, "instantánea" is the feminine form of the adjective "instantáneo," describing "respuesta" (response), signifying an immediate reaction.
La respuesta del sistema fue instantánea.
The system's response was instantaneous.
In this sentence, "instantánea" is used to characterize "gratitud" (gratitude) as immediate and occurring without delay.
Me encanta la gratitud instantánea que recibo por mi ayuda.
I love the instant gratitude I receive for my help.
The word "instantáneo" is used as an adjective to describe "café" (coffee), indicating that it is prepared quickly and without delay.