  This study delves into modified gravity theories that are equivalent to
General Relativity but involve the torsion or non-metricity scalar instead of
the curvature scalar. Specifically, we focus on $f(Q,T)$ gravity, which entails
an arbitrary function of the non-metricity scalar $Q$ non-minimally coupled to
the trace of the stress-energy tensor $T$. We investigate the functional form
$f(Q,T)=f(Q)+f(T)$, where $f(Q) =Q+\alpha\,Q^2$ represents the Starobinsky
model in $f(Q)$ gravity and $f(T)=2\,\gamma\,T$, with $\alpha$ and $\gamma$ are
constants. To obtain solutions for the Friedmann equations, we introduce the
concept of a constant jerk and employ its definition to trace the evolution of
other kinematic variables, including the deceleration parameter, energy
density, EoS parameter, and various energy conditions. These analyses serve to
validate the proposed model. We constrain our constant jerk model using the
most available Pantheon set of data, the Hubble set of data, and the BAO set of
data. Further, we employ $Om(z)$ diagnostic as a means to differentiate between
different theories of dark energy. Throughout our examination, all cosmological
parameters under scrutiny consistently indicate an accelerating Universe.
