Javier Castillo is a Spanish author known for his engaging thrillers and novels. He gained popularity with his debut book, "El día que se perdió la cordura," which was published in 2017. Castillo's writing often combines elements of suspense and mystery, captivating readers with intricate plots and well-developed characters. In addition to his successful novels, Castillo has a strong presence on social media, where he connects with fans and shares insights about his writing process. His works have been translated into several languages, expanding his readership beyond Spain and contributing to his growing international fame.