"Let's join two views and create a custom column that acts as a primary key so that other tables can treat it like a foreign key" said no dev ever.

Or at least I had thought that until today when I started figuring out why our queries are so goddamn slow. I hate the previous devs so much.

@kescherRant There is a difference between optimization and a general consideration of performance. With premature optimization you sacrifice clarity and other quality aspects for a supposed gain in performance. Simply considering the performance aspects of your code shouldn't effect other qualities if done the right way.
For example, using a data structure suitable for your expected workload can go a long way in improving performance. And if the data structure is nicely implemented, it's dead simple to implement as well.