From underdog start-up to industry leader, 40 years of strategic choices, innovative breakthroughs, and bold choices revealed. Lessons Learned of ASML traces the journey from an underdog start-up to the dominant supplier in a volatile Tech industry. Built on interviews, internal notes and archives, it reconstructs the managerial choices--how ambitions were set, investments staged, partnerships orchestrated, technologies chosen, and setbacks absorbed--and tests them across four decades. Each chapter applies a clear analytical lens and brief reflection prompts, bringing strategy, innovation and ecosystem coordination into one readable, evidence-driven narrative that opens theory for practice without pretending there is a universal recipe.