I once joined a Java team as a front-end dev (I'm full-stack). They would do the back-end. They had done everything by the book perfectly. Following all the best practices. But the back-end wasn't doing what it needed to do by a long shot. They were stuck. Meaning I couldn't make progress. So I cooked up a simple (temporary) PHP back-end so I could easily build the needed queries. All nicely secured with LDAP. I was literally running circles around their solution. But it was blasphemy.

Eventually they ported my code into Java. Some portions literally one-to-one. Nobody will ever know the critical role PHP played in this Java success story.