As an example, let's look at a common class of biocatalysts, proteases, which possess the ability to hydrolyse amide (as well as ester) bonds. This amide hydrolysis reaction is extremely challenging with a half-life of 450 years [9,10]. Protease enzymes make use of a catalytic triad (Figure 1a Abstract: We review recent developments in the use of short peptides in the design of minimalistic biocatalysts focusing on ester hydrolysis. A number of designed peptide nanostructures are shown to have (modest) catalytic activity. Five features are discussed and illustrated by literature examples, including primary peptide sequence, nanosurfaces/scaffolds, binding pockets, multivalency and the presence of metal ions. Some of these are derived from natural enzymes, but others, such as multivalency of active sites on designed nanofibers, may give rise to new features not found in natural enzymes. Remarkably, it is shown that each of these design features give rise to similar rate enhancements in ester hydrolysis. Overall, there has been significant progress in the development of fundamental understanding of the factors that influence binding and activity in recent years, holding promise for increasingly rational design of peptide based biocatalysts.