Metascience is the field of research on the scientific process. This includes the history and philosophy of science. What is science? What is science as a process? What practices and principles govern scientific exploration? The field of metascience – in all its interdisciplinary dimensions – is rapidly emerging as a new discipline itself. The recent Metascience 2019 Symposium has served as a formative meeting for metascience, or the “science of science”. The interdisciplinary dimensions that underpin metascience reveal themselves in a wide spectrum of meta-research topics, ranging from very practical concerns to deeply foundational questions. At the practical level, the so-called ‘reproducibility crisis’ has drawn attention to the every-day operations of laboratory science and how these can go wrong and can be improved. At the foundational level, long-standing questions in the metaphysics of science remain unresolved such as how scientific truth and scientific objectivity can be possible. Increasingly, multiple approaches from various disciplines contribute to accelerating the emergence of metascience as a fully integrated field of research in the 21st century.