This book constitutes the thoroughly refereed proceedings of the 15th International Conference on Collaborative Computing: Networking, Applications, and Worksharing, CollaborateCom 2019, held in London, UK, in August 2019. The 54 full papers presented were carefully reviewed and selected from 121 submissions. The papers reflect the conference sessions as follows: cloud, IoT and edge computing, collaborative IoT services and applications, artificial intelligence, software development, teleportation protocol and entanglement swapping, network based on the neural network, scheme based on blockchain and zero-knowledge proof in vehicle networking, software development.