[PigeonHolePncpl]

In my case, it was database optimizations that reduced the overall costs significantly

* Instead of writing big complex queries that had nested SELECT's, I split them into smaller bite-sized chunks that could be cached * Better caching strategies - reducing how many caches were flushed when a change was made * Tweaking the index's on database tables to improve WHERE clauses * Storing intermediate calculations into the database (for example, the number of posts a user has could be stored on the user table instead of counting them each time)

When I optimized the database, I could then reduce the size of the DB and the server as they no longer needed to work / wait as much