I thought Slack (Amazon) was just about time management, but actually it is a book about organisational dysfunction. I found it eye opening. At the heart of it is the idea that trying to optimise for efficiency is problematic, and the various dysfunctions that result.
Dysfunctions such as: busywork (need to appear busy, otherwise you’re underutilized and could be laid off), longer response times (because things pile up because everyone is so busy), cost saving measures that backfire (because e.g. engineers do their own admin work and there’s point where you need an extra engineer when an admin would be less expensive), and micromanagement.
It’s quite an old book, but didn’t feel dated so much as prophetic. Definitely worth reading.