Since the second CubeSat Industry Days event was held in June 2015, there has been a further progress in European CubeSat system capabilities, subsystem products/technologies, launch services, and mission operations experience. The market is widening, CubeSat industry growth continues to gather pace, and government as well as commercial customers are starting to utilise these small systems for science and applications. The ESA Technology programme has several CubeSat In-Orbit Demonstration (IOD) projects and technology development activities ongoing with industry/research institutes aimed at maturing enabling miniaturized technologies and getting them to orbit as quickly as possible. Significantly, CubeSat/nanosats have, for the first time, formed part of the ESA Technology programme approved by Member States at the Ministerial Council 2016. Furthermore, numerous CubeSat/nano-spacecraft related mission studies are underway or completed, including "beyond LEO" CubeSats for science and exploration. Additionally, CubeSat projects have recently been initiated in other ESA programmes too. The event serves as a forum to exchange information on the latest industry developments/future priorities and the ESA activities in the CubeSat nano-satellite domain, reflect on technology/mission roadmaps, as well as to discuss the technical/regulatory challenges facing the industry in sustaining further growth and competitiveness in this innovative and dynamic segment of the space sector.