The potential of big data is a focus of interest the world over. That is why École Polytechnique has made data science a priority in its research and training. In the Computer Science Laboratory, researcher Yanlei Diao is developing innovative algorithmic foundations to design a new generation of "big and fast data" systems. The progress she has made is opening up the way to continuous analyses, with short response times for large quantities of data, thereby allowing rapid transfers of information to numerous applications. The advent of "Big and Fast Data Analysis" promises to cause an upheaval in many areas of science and society, such as healthcare and the internet of things. In addition, the data science initiative, led by Emmanuel Bacry of X's Applied Mathematics Center, is looking into big data applied to healthcare and health economics. In this context, X and the CNAM, the French National Health Insurance Fund, have set up a research and development partnership to work on data science. This collaboration, which began at the end of 2014, has already led to new ways of exploiting the data in the SNIIRAM, the health system database that compiles all the data on the reimbursement of healthcare expenditure in France. On the training side, since 2016 X has offered a Master of Science and Technology degree entitled "Data Science for Business", a dual degree run with the HEC business school, which is intended to train data managers capable of taking strategic decisions based on data resources. Polytechnique also offers a Mathematics Master's in Big Data Science in conjunction with Télécom ParisTech, Université Paris-Sud, lNS Cachan and ENSAE ParisTech, to train data scientists and experts in the analysis and exploitation of big data. In continuing education, École Polytechnique Executive Education has already trained over 200 professionals in data science project management via its "Data Science Starter Program". In 2018, X was also involved in setting up a Data Science Master's program in Côte d’Ivoire. Finally, since 2017, École Polytechnique has organized a Data Science Summer School every year with interventions from data science experts.