  We investigate an interacting quintessence dark energy - dark matter scenario
and its impact on structure formation by analyzing the evolution of scalar
perturbations. The interaction is introduced by incorporating a non-zero source
term into the continuity equations of the two sectors (with opposite signs),
modeled as $\bar{Q}_0 \equiv \alpha\bar{\rho}_{\rm m}(H + \kappa\dot{\phi})$.
The coupling parameter $\alpha$ and the parameter $\lambda$ involved in
quintessence potential $V(\phi) = V_0e^{-\lambda\kappa\phi}$, play crucial
roles in governing the dynamics of evolution examined within the present
framework. The cosmic evolution, within this context, is depicted as a
first-order autonomous system of equations involving appropriately chosen
dynamical variables. We analyzed the associated stability characteristics and
growth rate of perturbations and obtained domains in the ($\alpha-\lambda$)
parameter space for which fixed points can exhibit stable and non-phantom
accelerating solutions. Depending on its magnitude, the coupling parameter
$\alpha$ has the potential to change the characteristics of certain critical
points, altering them from attractors to repellers. This model effectively
captures the evolutionary features of the universe across its various phases at
both the background and perturbation levels. The issue of cosmic coincidence
can also be addressed within the framework of this model. We also observed that
for a moderate strength of coupling, the growth rate of matter perturbation
extends into the distant future.
