  We aim to unravel the interior mixing profile of the pulsating eclipsing
binary KIC9850387 by comparing its dynamical parameters and the parameters
derived through a combination of evolutionary and asteroseismic modelling. We
created a grid of stellar evolutionary models using the stellar evolutionary
code \textsc{mesa} and performed an isochrone-cloud (isocloud) based
evolutionary modelling of the system. We then generated a grid of pulsational
models using the stellar pulsation code \textsc{gyre} based on the age
constraints from the evolutionary modelling. Finally, we performed
asteroseismic modelling of the observed $\ell=1$ and $\ell=2$ period-spacing
patterns, utilising different combinations of observational constraints, merit
functions, and asteroseismic observables to obtain strong constraints on the
interior properties of the primary star. Through a combination of asteroseismic
modelling and dynamical constraints, we found that the system comprises two
main-sequence components at an age of $1.2\pm0.1$ Gyr. We also observed that
asteroseismic modelling provided stronger constraints on the interior
properties than evolutionary modelling. Overall, we found high levels of
interior mixing and posited that this is a result of intrinsic non-tidal mixing
mechanisms due to a similar observed behaviour in single stars. We investigated
the high-frequency regime of KIC9850387 and found evidence of the surface
effect as well as rotational splitting in the form of a prograde-retrograde
dipole g$_{1}$ mode doublet with a missing zonal mode. We find that the
dynamical parameters and the parameters extracted from the asteroseismic
modelling of period-spacing patterns are only barely compliant, reinforcing the
need for homogeneous analyses of samples of pulsating eclipsing binaries that
aim to calibrating interior mixing profiles.
