Already know? I think that any technologies can pose a non boring challenges. These tend to happen when a technology is used at scale, or with an unusual use cases.

Look at 'boring' php, facebook was using this language at scale, so they had to develop a just in time compiler for the whole thing. Python didn't have that problem, so it still doesn't have a just in time compiler (for the default interpreter)

Also look at all the changes and action in the JDK (ever since JDK11). Is that also boring?