Casey generally, across all his material, advocates for non-pessimisation. Measurement takes too long to apply it to your entire program. He advocates for thinking about how much work the computer should actually have to do, then not making it do much more than that, at all times. This means avoiding serial dependency chains on the network, and huge towers of abstractions, and redundant work. He allows for writing lazy slow code as an intentional tradeoff that you may revise later if it becomes a bottleneck. He does not allow for inherently slow architecture.