"Sprint: How to Solve Big Problems and Test New Ideas in Just Five Days" is a book written by Jake Knapp, John Zeratsky, and Braden Kowitz. The book introduces a unique and practical approach to problem-solving and idea testing. It outlines a five-day process called a "sprint" that helps teams to quickly validate ideas, solve complex problems, and make progress on projects. The authors provide step-by-step instructions, real-world examples, and practical tips to guide readers through the sprint process. This book is a valuable resource for individuals and teams looking to accelerate innovation and make better decisions in a short amount of time.