I am not a software engineer, although I do write programs. What is it about digital infrastructure that requires maintenance? In the natural world, there is corrosion, thermal fluctuation, radiation, seismic activity, vandalism, whathaveyou. What are the issues facing the arxiv demanding the attention of multiple people 'round the clock?

They have to update the software stack, replace usage of deprecated APIs, support new latex packages etc. They could probably minimize these by limiting the scope but just keeping a small, tightly scoped software functional is always boring, people want to work on fun new features, they enjoy the brand recognition and feel like they should do more stuff.

I wonder when they will introduce the algorithmic feed and the social network features.