I did some consulting recently for a startup on the data observability space. Performance and scalability were terrible. Not to mention other subtle issues like

I did some consulting recently for a startup on the data observability space. Performance and scalability were terrible. Not to mention other subtle issues like terrible coupling between services, between classes, terrible abstractions, the inconsistency of the naming in the domain model (e.g. an object that had one name in a set of micro-services, but was named completely differently in the UI and front-end code. And in general, the culture of the company was about churning out features fast, at the cost of anything else. Not surprisingly, as customers started to scale up their deployments, the problems started arising. And yet, the CTO refused to even acknowledge my advice, my carefully done benchmarks, my numeric projections. It was completely alien for him. He didn't understand that system software requires a more careful approach than your usual B2C e-commerce MVP.