Drug discovery is an inherently multi-objective problem where numerous pharmaceutically important objectives need to be satisfied, with the added complications that often objectives can be: i. Conflicting (for example in a project where increased solubility and increased metabolic stability are required -even though increasing solubility can cause reducing metabolic stability), ii. Challenging to quantify or measure experimentally (e.g drug-likeness, synthetic accessibility objectives), and iii. The number of all potentially relevant objectives can be very large making the optimization landscape infeasible for most optimization algorithms; hence in practice a subset of objectives is usually selected and may need to be modified during the optimization process.