Quantum discrimination and estimation are pivotal for many 
quantum technologies, and their performance depends on the 
optimal choice of probe state and measurement. Here we show that
their performance can be further improved by suitably tailoring 
the pulses that make up the interferometer. Developing an optimal
control framework and applying it to the discrimination and 
estimation of a magnetic field in the presence of noise, we find 
an increase in the overall achievable state distinguishability.
Moreover, the maximum distinguishability can be stabilized for 
times that are more than an order of magnitude longer than the 
decoherence time.