Crisis on Infinite Earths was a huge undertaking for the DCTV shows, touching several television shows and movies in the history of DC adaptations.
Speaking to the Fake Nerd podcast, Crisis showrunner Marc Guggenheim spoke about why the crossover was a "satisfying" experience for audiences.
"Here's the thing: there's a lot of things that I think made 'Crisis on Infinite Earths' satisfying for people, but the thing that people don't talk about is, I think, one of the most important things, which is the fact that it was the culmination of eight years of worldbuilding." Guggenheim said.
He continued, "We didn't do this first time out of the gate. This is five hours and six shows that didn't all come into being all at once. Those six shows are the product of eight years. I'm not saying we have to wait another eight years, but I think one of the reasons why 'Crisis' was so satisfying was you did get a chance to watch the building blocks get put into place."
Crisis had been teased for years in the Arrowverse, with Lyla Michaels, aka Harbinger, appearing as a supporting character in the first season of Arrow. Meanwhile, for years on The Flash, a newspaper from the future teased Barry Allen's disappearance during a "Crisis". Ultimately the Flash of Earth-90 (John Wesley Shipp) would give his life to stop an anti-matter wave from destroying Earth-1.
Crisis on Infinite Earths is available to stream in its entirety on The CW App.