Danmarks Tekniske Universitet (DTU)

In general, PhD in DTU is very short, only 3 years. In this period it is difficult to publish papers, present papers at conferences and create a network. This university does not have internal money to fund researchers and it makes it difficult to keep their employees after finishing their contract.
Department of computer science in DTU lacks theoretical background. Generally, there are not a lot of smart students so do not increase your expectation by checking the ranking of this university.
It is a boring university, danish students do not hang out with international students and it is far from Copenhagen. Rent is hugely expensive in Lyngby and you probably should live some where far from DTU.