I was brought onto Sorted by a friend to help out with the accumulated technical debt within the game. For the four years before I joined, this project has been worked in entirely in blueprint by designers with very little coding knowledge.
Once I have joined, the project went through an engine upgrade, which, as one might know, isn't the best idea.
I had no experience with multiplayer beforehand. I just learned what replication is, and, on the next day, I receive a message akin to "Players cannot connect to each other. We have a build in an hour. We need help."
Needless to say, it was a quite fun trial by fire.
Afterwards, I was responsible for introducing new or reworking broken systems that facilitated the work on this project. Examples include death systems, tag-based events, and a dialogue manager.
A few months after I and other engineers joined, we managed to finally push this project out of development hell and publish it on Steam.