70% of this is required to be this complex as the sector we work in is very rule and workflow heavy and the customisation support is immensely complicated. 30% is hacked in stuff for single clients and legacy stuff from the dark ages that we had to hang on to.

We're breaking it down into tiny subsystems at the moment i.e. moving to a microservices architecture. I'm describing the "monolith" that we're starting from.

In time it'll have 1/2 the code, 2-5x the throughput and significantly less cost.