I would also like to give special thanks to Manuel Hermenegildo for his humility, selfless support and constant advice, and for transmitting his passion and enthusiasm in every talk and meeting.My sincere thanks also to John Gallagher, for welcoming me so generously and kindly as a visiting student in Roskilde, Denmark. It was an unforgettable experience to work with him in such beautiful land. I have acquired very valuable knowledge, useful both for my thesis and my life (for example, the importance of hygge).I would also like to thank Miguel Ángel Perpiñán, for generously sharing all his knowledge and expertise, which have been fundamental for the completion of this dissertation.I would like to express my gratitude to the IMDEA Software Institute, its former Director Manuel Hermenegildo and its current Director Manuel Carro, for funding my Ph.D. and providing me with such inspiring workplace. Thanks to the support staff for their permanent help and attention in every detail. Also, thanks to all the researchers, it has been the most amazing experience to share a work environment with some of the world top researchers in their respective fields.Many thanks to all my office mates and members of the CLIP group, both past and present, for encouraging me, listening to me, sharing their ideas and enduring my anxiety when deadlines were close: