The number of Blockchain (BC) platforms developed since the proposal of Bitcoin in 2009 continues to increase as the price of their underlying cryptocurrencies rises, and different use cases for such a concept are introduced. Further, given the lack of standards, each one of the myriads of BC platforms addresses specific issues, such as increasing transaction speed or lowering fees, in a particular manner and not considering the interoperability among platforms, which leads to data silos and ossification of BC-based applications. Further, the technical aspects introduced by such developments hinder the BC selection process for different use cases. Hence, this PhD thesis tackles such issues by designing, developing, and evaluating an environment composed of a toolkit to refine requirements expressed intents to policies, a policy-based framework to select the most suitable BC given such requirements, and an interoperability API that allows a transparent interaction with multiple BCs. Complementing these contributions, an intent refinement continuum environment is proposed to guide the refinement flow in the intent-based environment.