Reading "The Goal" and contemplating how to apply the Theory of Constrains to complex software systems a couple of decades ago became part of the secret sauce of my career as a software engineer. Especially helpful was the insigth that one may make good progress tuning one part of a system only to discover that a larger constraint prevails as the true bottleneck.

Here's a practical example. For those who may still wrangle fleets of actual cloud instances (instead of going the managed cluster or serverless route), a common mistake is to imagine that all that is needed is a group of the smallest compute units available. But with AWS, for example, this can bite you when the smallest instances also have dinky allowances for network and/or disk I/O compared to medium or larger instances. People end up wondering why their queues aren't draining quickly or their DB writes or log pipelines are backing up, etc.