Design sprint by Google is a 5-day process which helps to understand, whether an idea fits the needs of customers. This sprint doesn't assume the launch of MVP.
Here is how it happens:
Day 1: Aims and tasks are formulated. Studying of potential clients takes place, with a help of expert clients.
Day 2: Ideas are created. Basing on them sketches and outlines of decisions are drawn.
Day 3: The winning sketch is chosen. Then it is turned into a storyboard.
Day 4: A prototype is created.
Day 5: The prototype is tested on clients.
After the test the results are analyzed and changes are made. But this 5-day sprint can serve as a great opportunity to test product`s viability.