  The prediction of high $T_c$ superconductivity in layers of LaNiO$_3$ through
orbital engineering has led to extensive research efforts over the last fifteen
years. During this period, a plethora of thin films and heterostructures based
rare-earth nickelate family with perovskite structure has been synthesized and
explored. In this short perspective, we briefly review the complexity of bulk
$RE$NiO$_3$, spotlighting several recent findings of emergent phenomena in
heterostructures containing the interface between $RE$NiO$_3$ and another
transition metal oxide. Finally, we outline potentially interesting future
directions linked to time-domain dynamics to harness new Mott and topological
phases in artificial structures of $RE$NiO$_3$.
