The invention provides method for therapeutic protein drug development that incorporates therapeutic and/or formulation and/or manufacturing considerations in the early screening process. The approach involves screening a plurality of different variants of a domain that have been determined to have the desired therapeutic property to identify one or more variants that have desired therapeutic and/or formulation characteristics, and constructing the full multidomain proteins using the identified domain variants. The present invention also provides a method for determining the shelf life of multidomain proteins in formulations. The method comprises determining a thermal denaturation and/or renaturation curve of a domain of the protein whose unfolding leads to aggregation of the protein in a solution. The method evaluates the shelf life of the multidomain protein based on the denaturation/renaturation curve. The invention also provides methods for engineering multidomain proteins to improve their therapeutic and/or formulation characteristics.