Finished Designing Data-Intensive Applications. What next?
Papers, in small doses: the Dynamo paper for the tradeoffs, Raft for consensus you can actually follow, and the Google SRE book for how it fails in practice. Another textbook at this point adds vocabulary rather than understanding.
I read and forget. What note system survives?
Notes that answer questions you had, not summaries of chapters. A chapter summary is a worse version of the book; a note that says "this is why our retry storm happened" is retrievable years later because it is attached to a real problem.
Papers lose me at the equations.
Read the abstract, the conclusion, and the experimental setup first, and skip the proofs entirely on the first pass. Most of the transferable content of a systems paper is in what they measured and what surprised them.
Is there a simpler version that gets most of the benefit?
Yes: do the first step, skip the automation, and revisit in a month. Most of the value is in the first step, and most of the cost is in making it repeatable before you know it is right.