Over the past 15 years, LEGO has achieved what has come to be appreciated as the greatest U-turn in corporate history. In 2004 the Danish-born company was drowning in $800m of debt and was being hit by a 30% loss in sales year-on-year. Despite being arguably the most recognizable toy brand on the planet, 50 years on from it’s inception the plastic brick-maker was struggling to stay afloat in the midst of a rapidly changing market. Verging onto bankruptcy, something had to change. With the appointment of new CEO Jørgen Vig Knudstorp that same year, LEGO underwent a transformation that radically rebuilt the core business, brick by brick. By 2005, the company had turned its first profit in two years, it quadrupled its return between 2008 and 2010 and in 2015 it announced profits of $660m. Key to this transformation was the implementation of a culture of continuous improvement that had the strength and longevity to keep up with the company’s unprecedented growth. Here, we share essential insights from Peter’s 28-years of experience in the change sphere and his personal building blocks for continuous improvement.