Exactly. I've found that even with a greenfield project, there is the tension between keeping things simple and avoiding fully-engineering code so as to quickly

Exactly. I've found that even with a greenfield project, there is the tension between keeping things simple and avoiding fully-engineering code so as to quickly get to an MVP, and the fact that code that is under-engineered is creating technical debt that becomes more ossified the more you build on top of it. My current thinking on a solution to this conundrum is this: try to craft the best architecture and engineering you can up-front _vertically_, but drastically reduce the workload by paring things down _horizontally_.